# Aquarium sand and diatoms...



## dcurzon

So one of my tanks seems to be in a perpetual state of diatoms.  It was converted back to fish maybe 18 months ago or so, so easy to lose track of time.
Juwel Rio 125
2x 28w T5's.  These are old bulbs, probably at least 8 years.  Approx 8-10hrs a day.
Eheim 2215 - Intake rear right, spray bar along left side blowing down length of tank
CO2 via fire extinguisher and inline diffuser
Tank is in the lounge, so some light source other than over the tank.

My suspicion though, is that the sand I used might cause the problem. Bought from AMAZON in the photo's, its describes the product as "chosen from selected silicate aggregates blah blah"

I'm just in process of building a full-length spray bar to span the back to see if that helps at all, having just cleaned up every surface within again.  Plants seem to struggle to grow in this tank, although I have some Java ferns that seem to be doing 'ok'.


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## Jaseon

Im guessing the silicate sand is the problem. Im not sure if rinsing the sand does anything. I have read a post here somewhere saying silicate in the aquarium is not a trigger for diatoms so dont know. Maybe the connection between silicate, and diatoms is sending people down the wrong path.


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## dcurzon

who knows. I know one thing... I'll never use white sand again!!


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## jaypeecee

Jaceree said:


> Maybe the connection between silicate, and diatoms is sending people down the wrong path.


Hi @Jaceree 

No, I don't think so. The 'casing' (frustule) of diatoms is constructed from silicate.

JPC


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## Hufsa

Almost all inert aquarium sand is silica. Its not available to diatoms in this form.
@dw1305 knows more about it


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## jaypeecee

Hufsa said:


> Almost all inert aquarium sand is silica. Its not available to diatoms in this form.
> @dw1305 knows more about it


Hi @Hufsa 

If I remember rightly, the element silicon_ is_ available to diatoms but I can't remember the chemistry involved in this process. @dw1305 and I discussed this in a thread somewhere here on UKAPS. If I get a moment, I'll search for it. It took me by surprise when we made this discovery.

JPC


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## jaypeecee

Hi @Hufsa 

I found it! Here it is:









						Possible BBA and a host of questions
					

Hi @Marcus_F   I thought of one other possibility for a source of SiO2 - fish food. It may be used as a grinding aid in the preparation of fish meal, a common component of many processed fish foods.  JPC



					www.ukaps.org
				




Interesting, eh?

JPC


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## ceg4048

Jaceree said:


> Im guessing the silicate sand is the problem





dcurzon said:


> My suspicion though, is that the sand I used might cause the problem.



As mentioned above, neither sand nor silicates in the water column have anything to do with diatomic algae.
Troubleshooting has to begin with the basics such as review of lighting, CO2 and flow/distribution.
Did the issue arise 18 months ago? What is the gas/light schedule, etc. etc.

Cheers,


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## dcurzon

Cheers all...
Yes, diatoms since a couple of weeks into startup (as one would expect), and has been constant since.  
Actually a review of timelines and its nearer 12 months than 18.  Lockdown stir crazy.
I bought the tank 2nd hand, originally to house a rainbow crab.  The crab was in there for approx 8 years.  Diatoms were never an issue whilst used as a crab home, as they are land crabs so it was partially filled 50/50 land/water areas.  

With that in mind, I've never changed the T5's that are in it.  
Stock Juwel 2x28w T5's.
Lighting runs between 8-10 hours/day (because sometimes I'll put it on for an extra hour or 2 at night for viewing)
lights on/off: 12pm - 8pm
co2 on/off: 9am/3pm
co2 delivery: Inline diffuser to spraybar
I've recently removed a lot of plants for tank cleaning, with a replant when I feel the diatoms are a little more under control. So I've dialled the co2 down a bit in the interim,

Next steps:
So I need to make changes, watch, wait and see...
*Flow*
Spraybar was at one end, flowing the length of the tank.  What I noticed is that whilst the flow did reach and circulate, lots of crud ended up in the area below the spraybar. which was a bit of a dead spot.  Im experimenting with building a long spray bar to run along the back wall.  v1 was the Eheim extendable. Too many holes = not enough pressure. v2 is DIY, and much better, and the flow circulates front to back quite well.  However, holes are bigger than they need be, so v3 will be when I find a smaller drill bit 

*Light*
So I could replace the tired old T5's.  But I have my eyes on a few LED items on Ebay.  Light definitely also needs addressing.


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## GHNelson

Get some Ramshorn snails they will eat diatoms off everything!


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## dw1305

Hi all, 


GHNelson said:


> Get some Ramshorn snails they will eat diatoms off everything!


I'm a snail fan as well.


Jaceree said:


> Maybe the connection between silicate, and diatoms is sending people down the wrong path.


Yes, I think it is a case of 2 + 2 = 5.

Sand, glass, quartz and diatoms frustules are all made from silicon dioxide (SiO2), but so are some of the <"oldest rocks on earth">, and that is because it is very hard and <"totally insoluble in water">. 

I think of silicon dioxide (SiO2) as a bit like the nitrogen (N2) gas in the atmosphere, you <"can't equate N2 gas with nitrate (NO3)"> and you can't equate SiO2 with silicon. 

<"Diatoms are incredibly efficient"> at extracting silicon (Si) from solution, but that silicon has to be in the form of <"orthosilicic acids (H4SiO4)">.


> ..... _Diatoms are photosynthesising algae, they have a siliceous skeleton (frustule) and are found in almost every aquatic environment including fresh and marine waters, soils, in fact almost anywhere moist......_



cheers Darrel


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## jaypeecee

GHNelson said:


> Get some Ramshorn snails they will eat diatoms off everything!


Hi @GHNelson 

That may be correct but I find that Ramshorn Snails take over the tank and become a major problem in their own right. Perhaps you have mastered a method for controlling their population growth? If so, what's the secret?

JPC


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## dcurzon

GHNelson said:


> Get some Ramshorn snails they will eat diatoms off everything!


unfortunately clean up crew (snails/shrimp) wasn't really an option - tiger barbs and yoyo loach... However, yoyo loach seems to have vanished without a trace, which makes snails a possibility now.  Also wondering about some otto's unless the barbs will bother them too much


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## jaypeecee

ceg4048 said:


> As mentioned above, neither sand nor silicates in the water column have anything to do with diatomic algae.


Hi @ceg4048 

To what are you specifically referring when you say "As mentioned above..."? I take your point that sand and silicates may have nothing to do with growth of diatoms. But, that being the case, what then causes growth of diatoms?

JPC


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## Wolf6

I'm going with @Geoffrey Rea  's suggestion to just replace the sand periodically. Regularly turns brown or greenish for me as well  If that is the only thing not going entirely according to your wishes, but plants and fish are thriving, I wouldnt change too much.


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## GHNelson

jaypeecee said:


> Hi @GHNelson
> 
> That may be correct but I find that Ramshorn Snails take over the tank and become a major problem in their own right. Perhaps you have mastered a method for controlling their population growth? If so, what's the secret?
> 
> JPC


Haven't got fish..... so not any uneaten food to scavenge!


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## jaypeecee

ceg4048 said:


> As mentioned above, neither sand nor silicates in the water column have anything to do with diatomic algae.


Hi @ceg4048 

I thought I should re-visit this and found the following:









						Silicon, diatoms in aquaculture - Responsible Seafood Advocate
					

The silicon plants take up in silicic acid from water strengthens cell walls. Among the phytoplankton, diatoms particularly need silicon.




					www.aquaculturealliance.org
				




From the above link, I have extracted this:

"Studies of temperate-zone lakes have shown that diatoms often bloom in the spring, but this phenomenon leads to reduced silica concentration. Once the silica concentration declines, other types of phytoplankton that do not need silicon typically replace diatoms as the predominant form of planktonic algae".

The above quote and the article itself leads me again to the conclusion that diatoms and silicates are indeed correlated.

JPC


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## dcurzon

Maybe I need a bag of silicatex or similar in the filter for a while


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## jaypeecee

GHNelson said:


> Haven't got fish, so not any uneaten food to scavenge!


Hi @GHNelson

In the tank where I have had a Ramshorn Snail problem, there are also no fish or any other livestock. Just plants, driftwood and water. And no substrate.

JPC


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## Wookii

dcurzon said:


> unfortunately clean up crew (snails/shrimp) wasn't really an option - tiger barbs and yoyo loach... However, yoyo loach seems to have vanished without a trace, which makes snails a possibility now.  Also wondering about some otto's unless the barbs will bother them too much



I was going to suggest Oto's - they do require specific care, but they can clean a tank of diatoms in matter of days.


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## GHNelson

They lay eggs....but don't see young snails!


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## Wolf6

Wookii said:


> I was going to suggest Oto's - they do require specific care, but they can clean a tank of diatoms in matter of days.


They clean my plants, rocks, wood and windows, but I dont ever see them on the sand other then briefly lying on it. Do yours clean your sand too? And if so, how did you train them


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## dw1305

Hi all,


jaypeecee said:


> In the tank where I have had a Ramshorn Snail problem, there are also no fish or any other livestock.


They are doing well because they are eating the algae? If you really want to reduce their number, a slice of cucumber should collect quite few.

cheers Darrel


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## dw1305

Hi all,


Wolf6 said:


> Do yours clean your sand too?


Malaysian Trumpet Snails work for this, I don't if that is because they continually rebury the top layers of sand? or whether they actually eat the algae? 

cheers Darrel


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## Wookii

dcurzon said:


> Maybe I need a bag of silicatex or similar in the filter for a while



That's probably a slippery slope, and from what I have been advised by @dw1305 in the past, you will never be able to get the levels of silicates low enough to affect the diatoms - they can flourish on microscopic amounts.

They do appear to be very easily outcompeted by other organisms though, particularly other algae and plants, and possibly bacteria (?) which is perhaps why they're typically seen more in an immature tank.

Rather than silicate removers, your focus needs to be on whatever else in amiss with your set-up as Clive suggests. Something else is giving the diatoms an unnecessary advantage, or rather preventing the other higher organisms from establishing their dominance , if it is still persisting in your tank for 12 months.


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## Wookii

Wolf6 said:


> They clean my plants, rocks, wood and windows, but I dont ever see them on the sand other then briefly lying on it. Do yours clean your sand too? And if so, how did you train them



Mine happily feed off the sand, though I've not had any diatoms on it, so I haven't directly seen them eat those off it.  I'm more interested on how you've trained yours to clean your windows - that would save me a fortune on a window cleaner


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## John q

jaypeecee said:


> Once the silica concentration declines, other types of phytoplankton that do not need silicon typically replace diatoms as the predominant form of planktonic algae".



Just to throw a another spanner in the works and may be totally unrelated but if I reduce my light intensity I tend to get diatoms, if I increase it the diatoms disappear and gets replaced by algae. Trying to find that sweet spot in the middle is proving rather elusive atm.


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## dw1305

Hi all,


Wookii said:


> you will never be able to get the levels of silicates low enough to affect the diatoms - they can flourish on microscopic amounts.


That is my understanding, because they are almost universal anywhere there is liquid water including damp moss, wet soil etc. you can tell that silicon limitation isn't really an issue for them.

<"SilicatEx" is interesting">, because it may reduce diatom growth, but not by reducing the amount of silicon. It also removes phosphates (PO4---) and phosphorus is one of the major plant nutrients.


jaypeecee said:


> But, that being the case, what then causes growth of diatoms?


They have the same requirement for nutrient as all the other photosynthetic organisms, but with the addition of silica (Si).


jaypeecee said:


> I thought I should re-visit this and found the following:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Silicon, diatoms in aquaculture - Responsible Seafood Advocate
> 
> 
> The silicon plants take up in silicic acid from water strengthens cell walls. Among the phytoplankton, diatoms particularly need silicon.
> 
> 
> 
> 
> www.aquaculturealliance.org
> 
> 
> 
> 
> From the above link, I have extracted this:
> 
> "Studies of temperate-zone lakes have shown that diatoms often bloom in the spring, but this phenomenon leads to reduced silica concentration. Once the silica concentration declines, other types of phytoplankton that do not need silicon typically replace diatoms as the predominant form of planktonic algae".


I don't think any-one is saying that diatoms don't require silicon (Si), but I'm not sure that you can say that there is a correlation between silicon concentration and diatom growth in our tanks, particularly if you have higher plants (this is an aquaculture paper where the only plants are phytoplankton). Later on in the same publication it says:


> _........... and it is not known how low the silica concentration must fall before diatom growth is negatively affected..........It would be desirable to know the relationship between silica concentration and diatom growth, but this topic has not been investigated in aquaculture ponds. Lack of information about the relationships between silicate fertilization rates and silica concentrations in water, and how fast silica disappears from water also complicates efforts to encourage diatom growth.........._


I always have snails in my tanks and I very rarely have any apparent diatoms (there will be diatoms present, because diatoms are pretty much universal in liquid water).

I'm willing to speculate that every fish keeper has diatoms in their tanks, unless they keep their tanks in total darkness.

cheers Darrel


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## jaypeecee

GHNelson said:


> They lay eggs....but don't see young snails!


Hi @GHNelson

That's interesting. What's your secret? Do you have any water parameters that may explain this? I know that some critters' eggs only hatch under certain conditions. GH, KH, and temperature immediately spring to mind.

JPC


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## jaypeecee

dw1305 said:


> I don't think any-one is saying that diatoms don't require silicon (Si),


Hi @dw1305

Only @ceg4048 can give a definitive answer to this, I guess. Because it was his statement below that I was addressing. Have I misunderstood what he was saying here?

"neither sand nor silicates in the water column have anything to do with diatomic algae"

If it's me that's got the wrong end of the stick, then fair enough. But, as sand/silicates are SiO2 and particularly if an aquarist is using tap water, then surely diatoms will utilize the silicic acid? In which case, sand/silicates in the water column _will have_ a bearing on the growth of diatoms.

JPC


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## jaypeecee

John q said:


> Just to throw a another spanner in the works and may be totally unrelated but if I reduce my light intensity I tend to get diatoms, if I increase it the diatoms disappear and gets replaced by algae. Trying to find that sweet spot in the middle is proving rather elusive atm.


Hi @John q 

That's aquatics for ya!

JPC


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## GHNelson

jaypeecee said:


> Hi @GHNelson
> 
> That's interesting. What's your secret? Do you have any water parameters that may explain this? I know that some critters' eggs only hatch under certain conditions. GH, KH, and temperature immediately spring to mind.
> 
> JPC


I have very high TDS out the tap 355!
Obviously this can go a lot higher if I dose ferts and I neglect the water changes.


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## jaypeecee

GHNelson said:


> I have very high TDS out the tap 355!


Hi @GHNelson

Yes, that's 555 microS/cm which, as you say, is high. I'm going to look into this further. If the tank inhabitants are all OK with hard(er) water, this may be a way of keeping Ramshorn numbers to a minimum.

JPC


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## ceg4048

jaypeecee said:


> Hi @dw1305
> 
> Only @ceg4048 can give a definitive answer to this, I guess. Because it was his statement below that I was addressing. Have I misunderstood what he was saying here?
> 
> "neither sand nor silicates in the water column have anything to do with diatomic algae"
> 
> If it's me that's got the wrong end of the stick, then fair enough. But, as sand/silicates are SiO2 and particularly if an aquarist is using tap water, then surely diatoms will utilize the silicic acid? In which case, sand/silicates in the water column _will have_ a bearing on the growth of diatoms.
> 
> JPC


Yes, perhaps you misunderstood. As Darrel mentions, algae consume all the same types nutrients that are present but there is no correlation between the nutrient level present and the rise of the algae. Just because silicates are present this does not automatically mean that a diatomic algal bloom is present. Algae require PO4 but PO4 does not trigger algal blooms. Similarly BGA require Nitrogen, but we can cure a BGA bloom by increasing the concentration level of NO3 in the tank.

As usual, it's very easy to take the results of studies out of context and to automatically ascribe the conclusions of cause and effect in those studies to our tanks. It's vital to understand what data we can use and what we can ignore. Algae behave differently depending on the environment, so for example in marine tanks, PO4 can trigger algae but in freshwater tanks this does not happen. The study you reference discusses the effects in temperate lakes and in seawater, neither of which are the same as a freshwater aquarium.

We need to understand that algae require only microscopic amounts of nutrients, so they really do not care how much nutrients are in the water. The main culprits are excessive lighting and chemical instability in the tank. Every one of our tanks has BGA, hair, BBA, diatoms, GSA, and all the rest of the known algal types sitting in the tank waiting for conditions to be be favorable for them.
Conditions favorable for algae are usually conditions unfavorable for plants. There is a relationship between plants and algae in the tank as well as in natural (or manmade) bodies of water, but those relationships are very different from body to body. 

We can never eradicate algal spores from the tank, however we can practice good plant husbandry and in this way minimize the frequency and severity of their blooms. Algal blooms therefore cannot be resolved by limiting this nutrient or that nutrient and it is therefore unwise and ineffective to pursue the policy of nutrient eradication because doing so will usually lead to eradication of the very plants we hope to grow.

Cheers,


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## dw1305

Hi all, 


jaypeecee said:


> But, as sand/silicates are SiO2 and particularly if an aquarist is using tap water, then surely diatoms will utilize the silicic acid? In which case, sand/silicates in the water column _will have_ a bearing on the growth of diatoms.


I understand what you are saying, but I still think we are in "_apples and pears_" territory.  

Sand, glass, quartz, Diatom frustules and moler clay are all made of <"SiO2">, but none of them are soluble in the tank.  The <"Baltic Shield rocks">, <"Lewisian gneiss"> or <"Gunflint chert"> are largely made of quartz  and they are billions of years (10^9) old.  If they had any solubility what so ever, at standard temperatures and pressures even the minutest amount, they would have dissolved aeons ago.  

At high temperatures and pressures you can get silicon in solution (it is how you get bands of quartz in rocks etc.) and that is the silicon that ends up as traces of orthosilicic acid in rivers, streams, aquifers, tap water, the sea etc. 

Diatoms extract orthosilicic acid from water to build their frustules, and they are incredibly efficient at it, we know this because nearly all liquid water contains diatoms. If we removed *all of the orthosilicic acid* from our water we would stop diatom growth, but it would literally have to be *all of it.* 

The diatoms can't re-solubilise the silicon from their frustule, because it is quartz (SiO2) and that frustule will remain as <"insoluble quartz for all of eternity"> at normal temperatures and pressures. 


> _...... Moler and diatomite consists of fossilised remains of a special type of hard-shelled algae, which gives the material its unique organic structure. Diatomite in general is over 30 million years old – the Danish Moler was formed more than 50 million years ago ....._



cheers Darrel


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## jaypeecee

Hi @dw1305 

Thanks for your reply.

It seems as if the crux of this is that:

[1] Sand, quartz, silica and all forms of SiO2 _in the tank itself_ are not going to encourage growth of diatoms due to lack of solubility

[2] Silicic acid in tap water may encourage and support the growth of diatoms. This assumes that additional silicic acid will be added at water changes.

JPC


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## jaypeecee

Hi @ceg4048 

I am a (retired) physicist and you are a plant biologist. Therefore, you are the teacher and I'm the pupil. So, my objective is to better understand the points you are making. Taking some of these points, let's start with the following:



ceg4048 said:


> Algae require PO4 but PO4 does not trigger algal blooms. Similarly BGA require Nitrogen, but we can cure a BGA bloom by increasing the concentration level of NO3 in the tank.



What, in your experience 'triggers' algae blooms? This implies to me that a number of conditions, when simultaneously present, will flick a switch and algae starts growing. It's what might be called a binary switch. What I'm hearing is that it's not a_ gradual_ process. Now, let's turn to Cyanobacteria/BGA. I've run several experiments in one of my tanks with cyanobacteria. I identified the cyano as Oscillatoria. Why does increasing NO3 cure a BGA bloom?

Let's leave it at that for the moment but I may have other questions for you.

JPC


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## dw1305

Hi all,


jaypeecee said:


> Silicic acid in tap water may encourage and support the growth of diatoms.


It will definitely support the growth of diatoms, encourage is more open to question. My guess would be that it doesn't, purely because of the efficiency of diatoms in extracting silicon from any water source, so "some" is always going to be "enough".

While silicon (Si) isn't usually quoted as an essential plant nutrient, some plants extract silica (presumably also from orthosilicic acid) and use it for both stem strengthening and <"as a deterrent to grazing">. The most common examples are the phytoliths in grasses (think of Bamboo) and in Horsetails (_Equisetum_ spp.). 

A heavily silicified water plant is Hornwort - _Ceratophyllum demersum_, which has been <"reported to reduce diatom growth">, although allegedly via allelopathy rather than direct competition for silica.

cheers Darrel


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## jaypeecee

dw1305 said:


> While silicon (Si) isn't usually quoted as an essential plant nutrient, some plants extract silica (presumably also from orthosilicic acid) and use it for both stem strengthening and <"as a deterrent to grazing">.



Hi Darrel (@dw1305)

Interestingly, neither silicon nor silicates nor diatoms get a mention in the index of Diana Walstad's book, _Ecology of the Planted Aquarium_. Nor The 2Hr Aquarist. So, it's obviously not considered important to the growth of aquarium plants. At least, by some. But, take a look at the following:

https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2435.12614

JPC


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## dw1305

Hi all, 


jaypeecee said:


> neither silicon nor silicates nor diatoms get a mention in the index of Diana Walstad's book, _Ecology of the Planted Aquarium_. Nor The 2Hr Aquarist.


My guess is that in heavily planted tanks you don't really get obvious diatom blooms, certainly not after the initial start up phase. 


jaypeecee said:


> But, take a look at the following:
> 
> https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2435.12614


Thanks for that, that looks an interesting paper. 

cheers Darrel


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## ceg4048

jaypeecee said:


> What, in your experience 'triggers' algae blooms? This implies to me that a number of conditions, when simultaneously present, will flick a switch and algae starts growing.


For clarification, I'm a plant grower - just another guy off the street. Darrel is the biologist. 
In any case, since we have all the spores present in the tank it's a race to see which species can conquer the tank. Different algae are triggered, as you mention, by a combination of and variety of conditions. We don't yet have the full story down to the last atom, but at the macroscopic level we have pretty good correlations - as well as pretty good non-correlations which is actually easier to determine by FAR. 
We've divide causality by; nutrient deficiency related, CO2 deficiency related, or the combination. Of course it's not just these main categories as there are other factors such as Oxygen deficiency and general chemical instability.
As far as the general categories ;
The "known" CO2 related algae are Hair (and other filamentous types) and BBA. I put the word known in quotes because these are strongly correlated.
The "known" nutrient related is primarily BGA which is _typically _correlated with poor NO3.
The remaining species are correlated to the combination of poor CO2 and poor nutrient levels, the most prevalent of which is GSA, which is correlated to some combination of poor CO2 and poor PO4. When troubleshooting GSA, one has to analyze the tank keeping in mind that poor CO2 usually will show multiple symptoms - primarily structural faults in the plants, so if no other CO2 related symptoms are evident we then assume the GSA is related to PO4 deficiency. It's easy to add more PO4 and to observe the results. Do the easy thing first. Correcting a CO2 fault is exponentially more difficult.

Diatoms are in a different category and are typically triggered by the chemical instability. There are over 10,000 species. Normally the arise in newly setup tanks and then disappear after a few weeks - but they can be prolonged in the tank if the conditions do not stabilize. Change the water frequently, physically clean the tank and avoid excessive lighting.

Again, we're talking about a planted tank here, not a lake or marine tank or even a fish-only freshwater tank.

It's believed that spores monitor the environment and monitor the plants response to that environment. The mechanism is unclear, to me at least. Deficiency leads to decline in health, which results in degeneration of the plants tissues. The damaged tissues leak their contents into the water column and it is believed that the spores have the ability to detect the contents of the leak and respond by blooming. Healthy plants grow, are tight and are able to resist the attacks. So in these tanks there is a relationship between algae and plants wherein plants are prey and algae are predators.

Few people in The Matrix ever consider this relationship. They just consume regurgitated wives tales and run out to buy delusional test kits and other props such as "phosphoguard" or "nitrazorb", or whatever is fashionable. A tank free of algal blooms is hard work and it's not likely to happen when we fear nutrients or allow a test kit to determine our fate.

Also regarding  the article you referenced, I reckon it's another case where the data is taken out of context. I repeat the we have to be careful. The article does not imply that Si is a macronutrient for macrophytes. It is arguing that Si can be taken up by plants when the ambient concentration is high and that they can store high tissue concentration when necessary. Take a look at the first bar chart in Figure 1. It shows a case where in emergent growth, the tissue concentration is about 10,000 ppm Si where the ratio between the tissue concentration and concentration of the dissolved Si in the water is about 2.5. That means the water column Si concentration is about 4000 ppm. Were there diatomic blooms in the water at that concentration level? Unknown.

This demonstrates a win-win in that under the right conditions we can throw the kitchen sink at plants and they will gobble it up. This tells us what we know that plants clean up the environment.

Cheers,


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## jaypeecee

Hi @ceg4048 

Many thanks for your reply. I will read it several times in order to absorb the points you have made. I'm not sure what _The Matrix_ is - a book or a film, perhaps? BTW, the test kits I choose to use are not "delusional" for me. Indeed, I find them very beneficial but I recognize that some aquarists prefer not to use them.

Until later...

JPC


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## Karmicnull

jaypeecee said:


> I'm not sure what _The Matrix_ is


In this context vernacular for the internet . Or more accurately "people using social media and other internet knowledge sources"


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## jaypeecee

Karmicnull said:


> In this context vernacular for the internet . Or more accurately "people using social media and other internet knowledge sources"


Hi @Karmicnull 

And, apparently, it _is_ a film/movie:









						The Matrix - Wikipedia
					






					en.wikipedia.org
				




So, somewhere in my meanderings, I must have seen references to this. To be fair, it does look moderately interesting.

JPC


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## JoshP12

Hi all!

I struggle so much with the statement below, and I think it is just definitions.


ceg4048 said:


> Diatoms are in a different category ... and avoid excessive lighting.



I wanted to layout my thoughts to help tease this apart.

Light is a requirement for plant growth. It drives overall nutrient demand.

** * * Suppose the PAR at a point in the tank (and at a plant) is a value (call it 50). For that value (50 umol), that plant will require a unique amount of each: CO2, O2, nutrients, flow pattern, hormones, vitamins, etc -- AT that set moment in time. As time passes, clearly this changes. And we can assume that an aquarist, with appropriate attention, CAN balance this * * * *

There are several maximums that we can consider:
1) Maximum lighting for a moment in time for the tank given a fixed flow, CO2, etc etc etc etc SUCH THAT we have no visible algae and "healthy" plant growth (this is obviously unique and a ridiculous metric but I think anyone reading knows what I mean here)
2) Maximum lighting to obtain "maximum" growth for a set number of species (kind of like EI theory)
3) Maximum for species
4*) The maximum light PRE-photooxidation of tissue (obviously variable at depths)
5) etc etc

Now, given the maximum light for a moment in time for the tank in question (situation 1), then, let us define excessive lighting as light over that maximum PAR such that FOR SOME REASON the algae spores take advantage (i.e. the competition tips in their favor).

In this case, I agree that excessive lighting can continue an algae bloom/trigger it. However, refer to  **_, we can simply accommodate and "prevent the bloom" - thus the value of excessive lighting increases and so on, until we reach the maximum such that photooxidation has NOT occured yet for our plant mass (remember this is for a given moment in time) -- situation 4_.

Now, the elusive maximum that I have suggested (for situation 4*) is dependent on a few things:
1) The amount of chlorophyll degradation that the plant has self-induced as a protective measure
2) ... naturally, the colour.

At point 2, I bring it back to diatoms. They are brown, and they cannot change their color (why I do not know ... but I've never seen a green diatom and if someone has, then perhaps it has an adaptability similar to that of a plant and should not be a protist ... but this one is for Darrel  @dw1305.

A brown colour by definition absorbs more wavelengths of light than something that is a single colour. Now, it is not so simple as colours don't SIMPLY reflect one thing exclusively - unless we use perfect chemistry - so in a plant it may not be so simple.

But going with this, if we increase lighting and by *** balance everything up to  (and just before we reach) situation 4* for our plants, THEN we can potentially reach situation 4* for diatoms and FORCE them to absorb more photons than they can handle. As a result, the electromagnetic force may break the bonds of the diatom and incinerate it (like a laser on us).

So, excessive lighting by the definition above, certainly will trigger/encourage algae blooms. But an increase in light, properly approach via *_, could potentially reach the threshold of 4 for diatom vs 4_ for plants and provide us an advantage.

Further, that increase lighting, properly approached via *** and under 4*, could increase growth rates tipping the favor of the dynamic system towards plant growth (my own thoughts and I cannot prove it) ... AND incinerate the diatoms ... curing the issue.

Please help .

Josh


----------



## dw1305

Hi all,


JoshP12 said:


> They are brown, and they cannot change their color


They share <"some photosynthetic pigments with all other autotrophic organisms">, but they also have some that are only found in the <"Diatoms and Brown Algae">.






> _......... Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle........._



cheers Darrel


----------



## jaypeecee

Hi @JoshP12 

I am having a lot of difficulty following your reasoning. But, I'm very prepared to accept that it's my aged brain that is the problem. This is a difficult discussion to be having when we are unable to communicate by actually talking about it, isn't it?

JPC


----------



## JoshP12

jaypeecee said:


> Hi @JoshP12
> 
> I am having a lot of difficulty following your reasoning. But, I'm very prepared to accept that it's my aged brain that is the problem. This is a difficult discussion to be having when we are unable to communicate by actually talking about it, isn't it?
> 
> JPC


I would love to join a virtual Conference by UKAPS!!!

I suppose I went for rigour to eliminate any “holes being poked”

Here is what I mean:
Diatoms cannot handle as much light as plants since they are brown. They absorb more wavelengths. So, we can laser them before killing our plants. People can run high PAR algae free without killing everything - so what is excessive light? Just balance the light below the point of incinerating the plants, and then you can incinerate the diatoms.

The same may be said for BBA. But, is it the plants becoming healthy that eliminates them or the light? No clue - but I still don’t know what excessive light means.

My attempt for rigour is in the other post - but perhaps the above is better.


----------



## jaypeecee

Hi @ceg4048 

I would like to home in on the following:



ceg4048 said:


> The remaining species are correlated to the combination of poor CO2 and poor nutrient levels...



With CO2, you can get an idea of CO2 concentration from the humble drop checker. But, how do you categorically know that you have "poor nutrient levels" if you don't measure these with test kits or other instruments? I guess you may be fortunate enough to tell just by looking at a plant. I had a case recently where some floating plants were suffering. None of the plant deficiency symptoms charts helped one iota. Growth was stunted and there was some yellowing of the leaves. To my untrained eye, I suspected nitrogen, iron, magnesium or manganese deficiency. I tested the first three of these nutrients but all was OK. So, I then decided to test for inorganic phosphate and it was <0.02 mg/l. I added a phosphorus compound to the water and the plant perked up.



ceg4048 said:


> Diatoms are in a different category and are typically triggered by the chemical instability.



To which chemical(s) are you referring? The (Boyd) article that I referenced previously would suggest silicic acid.

That's enough for the moment.

JPC


----------



## jaypeecee

JoshP12 said:


> I would love to join a virtual Conference by UKAPS!!!


Hi @JoshP12 

Now, there's an _excellent_ idea. One for @LondonDragon, perhaps?

JPC


----------



## jaypeecee

JoshP12 said:


> My attempt for rigour is in the other post - but perhaps the above is better.



Hi @JoshP12

The two posts can happily coexist.

JPC


----------



## LondonDragon

jaypeecee said:


> Hi @JoshP12
> 
> Now, there's an _excellent_ idea. One for @LondonDragon, perhaps?
> 
> JPC


We have considered this already, like an evening with the experts kind of thing, will put a bit more thought into it 😉👍


----------



## Wookii

jaypeecee said:


> Hi @ceg4048With CO2, you can get an idea of CO2 concentration from the humble drop checker. But, how do you categorically know that you have "poor nutrient levels" if you don't measure these with test kits or other instruments? I guess you may be fortunate enough to tell just by looking at a plant. I had a case recently where some floating plants were suffering. None of the plant deficiency symptoms charts helped one iota. Growth was stunted and there was some yellowing of the leaves. To my untrained eye, I suspected nitrogen, iron, magnesium or manganese deficiency. I tested the first three of these nutrients but all was OK. So, I then decided to test for inorganic phosphate and it was <0.02 mg/l. I added a phosphorus compound to the water and the plant perked up.



To be honest that precisely why EI dosing exists and is so popular. Many of us simply aren’t experienced enough to look at changes to plants and diagnose specific nutrient deficiencies accurately.

With EI dosing is a case of prevention rather than cure, and simply eliminating nutrient deficiency as a possible cause of plant issues. If we accept that slight excesses of nutrients don’t cause algal blooms, particularly in mature tanks - and it has been proven often enough how to be beyond doubt - then there is no need not to dose an excess and ensure plants are never deficient.

That then leaves us far fewer ‘dials to turn’ when trying to diagnose any issues.


----------



## JoshP12

Wookii said:


> To be honest that precisely why EI dosing exists and is so popular. Many of us simply aren’t experienced enough to look at changes to plants and diagnose specific nutrient deficiencies accurately.


Love the way this is put - thanks for drafting it.

EI teaches us a lot.
How to do co2, water change, maintenance, flow patterns, light, trimming, dry salts, economic choices, the issues with the companies in this hobby lol and so on.

But it is baptism by fire. It tells you if something is off pretty fast.

You “can’t” learn to diagnose nutrient deficiencies without ample experience and/or being able to rule out all of those things EI teaches you.

Just some thoughts! 
Josh


----------



## jaypeecee

Wookii said:


> To be honest that precisely why EI dosing exists and is so popular. Many of us simply aren’t experienced enough to look at changes to plants and diagnose specific nutrient deficiencies accurately.


Hi @Wookii 

I hear what you say and it's a good point. But, I've avoided EI because it's very labour-intensive, isn't it? 50% water changes every week (at least). I don't want to become a slave to my tank(s) - I want to enjoy looking at them. Or, have I got it all wrong? And, now that I'm over 65, I don't think I can manage lugging all that water around. I don't have the stamina. Perhaps I should take up stamp collecting instead. 

JPC


----------



## Wookii

JoshP12 said:


> Love the way this is put - thanks for drafting it.
> 
> EI teaches us a lot.
> How to do co2, water change, maintenance, flow patterns, light, trimming, dry salts, economic choices, the issues with the companies in this hobby lol and so on.
> 
> But it is baptism by fire. It tells you if something is off pretty fast.
> 
> You “can’t” learn to diagnose nutrient deficiencies without ample experience and/or being able to rule out all of those things EI teaches you.
> 
> Just some thoughts!
> Josh



I guess it depends on your personal objectives, if you want to ‘learn’ how to identify deficiencies then attempting to avoid them by dosing excess nutrients won’t allow you to learn that directly.

But looking at it a different way, if you wanted to induce that learning experience in a controlled way, then you could establish good healthy plant growth under an EI dosing regime, and then simply limit one nutrient at a time whilst keeping the others on excess. At least then you have the chicken before the egg and know what is going to be causing the deficiencies before you start to observe them appearing!


----------



## Wookii

jaypeecee said:


> Hi @Wookii
> 
> I hear what you say and it's a good point. But, I've avoided EI because it's very labour-intensive, isn't it? 50% water changes every week (at least). I don't want to become a slave to my tank(s) - I want to enjoy looking at them. Or, have I got it all wrong? And, now that I'm over 65, I don't think I can manage lugging all that water around. I don't have the stamina. Perhaps I should take up stamp collecting instead.
> 
> JPC



Depends on how you set things up to be honest John - all my water changes are automated as lugging water or hose pipes around sucks the fun out of if for me too. That’s being said I personally consider a 50% weekly water change a minimum irrespective of dosing, if you have a reasonable amount of live stock.


----------



## jaypeecee

Hi Gareth (@Wookii)

Good to be 'talking' with you.

When you do your 50% water changes, do you also clean out the canister filter?

JPC


----------



## jaypeecee

Hi Gareth (@Wookii)

Perhaps we should discuss this by PM/Conversation. It's my fault going off at a tangent.

John


----------



## dw1305

Hi all, 


Wookii said:


> Many of us simply aren’t experienced enough to look at changes to plants and diagnose specific nutrient deficiencies accurately.


I don't think any of us can really diagnose specific nutrient deficiencies. We can make guesses based on the plants requirements, they need most of the macronutrients nitrogen (N), phosphorus (P) and potassium (K),  most UK tap water doesn't contain much magnesium( Mg), iron (Fe) is likely to be unavailable in hard water etc.

Iron deficiencies occur in new leaves and pale new growth is likely to be an iron deficiency, after that nearly all the other nutrients are mobile within the plant, and there are a huge number of possible combinations of nutrients that might cause deficiency symptoms in older leaves.

cheers Darrel


----------



## Wookii

jaypeecee said:


> Hi Gareth (@Wookii)
> 
> Good to be 'talking' with you.
> 
> When you do your 50% water changes, do you also clean out the canister filter?
> 
> JPC



Just the pre-filter, which takes a about 5 minutes, the main filter then about every 2-3 months.



jaypeecee said:


> Hi Gareth (@Wookii)
> 
> Perhaps we should discuss this by PM/Conversation. It's my fault going off at a tangent.
> 
> John



Yeah, feel free to drop me a PM at any point John.


----------



## ceg4048

JoshP12 said:


> Here is what I mean:
> Diatoms cannot handle as much light as plants since they are brown. They absorb more wavelengths. So, we can laser them before killing our plants. People can run high PAR algae free without killing everything - so what is excessive light? Just balance the light below the point of incinerating the plants, and then you can incinerate the diatoms.
> 
> The same may be said for BBA. But, is it the plants becoming healthy that eliminates them or the light? No clue - but I still don’t know what excessive light means.


The answer is no. All of these statements are wrong. In fact it's just the opposite and brown has nothing to do with anything.


jaypeecee said:


> With CO2, you can get an idea of CO2 concentration from the humble drop checker. But, how do you categorically know that you have "poor nutrient levels" if you don't measure these with test kits or other instruments?


Well, you'll have to spend a lot of money to find an instrument that can accurately and consistently measure nutrient levels. You'll not know from a hobby test kit reading


jaypeecee said:


> Growth was stunted and there was some yellowing of the leaves. To my untrained eye, I suspected nitrogen, iron, magnesium or manganese deficiency. I tested the first three of these nutrients but all was OK. So, I then decided to test for inorganic phosphate and it was <0.02 mg/l. I added a phosphorus compound to the water and the plant perked up.


Yeah, something else was going on or you did something (or didn't do something) that is unaccounted for. PO4 cannot fix yellowing. That isn't it's function. That's the function of Nitrogen and some micronutrients such as Iron.


jaypeecee said:


> To which chemical(s) are you referring? The (Boyd) article that I referenced previously would suggest silicic acid.


Chemicals such as NH3/NH4, organics and so forth.
No, as I mentioned it doesn't suggest anything of the sort because it addressed higher plants, not algae, and it was a very specific scenario, not one that we encounter in our tanks.


JoshP12 said:


> You “can’t” learn to diagnose nutrient deficiencies without ample experience and/or being able to rule out all of those things EI teaches you.


I don't know what the big deal is. I mean, everything we do has to be learned. Why is this so difficult? We have provided all of the the information necessary. 95% of our problems is CO2 related. After that one only needs to think about the the macronutrients. Even so, if one has difficulty, then just add more of everything. That way one need not think.

But no, everyone want to buy a test kit and play pharmacist. Then the kit tells lies and off we go to see the wizard of Oz.
_That's_ why you have difficulty. How hard is it to keep what Darrel just said in mind? If new leaves have discoloration it's a micronutrient problem, if it's old leaves then its a macronutrient problem. If it's micronutrient issue why on Earth would you just add one micronutrient? Add all of them because they are all suspect. This policy is so easy that trying to isolate a single micronutrient becomes absurd. How many times do we need to say that if you are adding nutrients, especially EI level of nutrients and are still showing deficiency then that means you have a flow/distribution issue and you need to fix that, not add more of anything.

Cheers,.


----------



## jaypeecee

ceg4048 said:


> Well, you'll have to spend a lot of money to find an instrument that can accurately and consistently measure nutrient levels. You'll not know from a hobby test kit reading





ceg4048 said:


> 95% of our problems is CO2 related.



Hi @ceg4048 

Do you have scientific evidence in support of the generalized statements above? The terms "accurately" and "consistently" need to be qualified. I am satisfied that many, but not all, hobby test kits are sufficiently accurate and reliable to justify their use. Otherwise, _for me_, it's all just guesswork. I don't have the experience to just look at an ailing plant and say it's deficient in X or Y. Dismissing all hobby test kits out of hand is something I can't get my head around. I am also OK with agreeing to disagree on these topics that seemingly divide people. Let's leave it at that - please.

JPC


----------



## ceg4048

jaypeecee said:


> Hi @ceg4048
> 
> Do you have scientific evidence in support of the generalized statements above? The terms "accurately" and "consistently" need to be qualified. I am satisfied that many, but not all, hobby test kits are sufficiently accurate and reliable to justify their use. Otherwise, _for me_, it's all just guesswork. I don't have the experience to just look at an ailing plant and say it's deficient in X or Y. Dismissing all hobby test kits out of hand is something I can't get my head around. I am also OK with agreeing to disagree on these topics that seemingly divide people. Let's leave it at that - please.
> 
> JPC


Hi JPC,
           Why is it always the victims of disinformation who are obliged to provide scientific evidence? I mean, why aren't the test kit makers and test kit lovers ever asked for scientific evidence? You may be aware that Einstein, when asked whether his theory of relativity could be proven, responded; "No number of experiments that agree with the theory can ever prove the theory as fact, but it only takes one experiment to disprove it." That's why 100 years later it is still referred to as The Theory of Relativity.

So taking this tack is how we collectively arrived at our conclusions. Using samples of RO water with known solute concentration levels and using the kits to compare with those known values the kits often fail. Even if they are close or bang on a few times, statistically they exhibit random successes. So this is how they behave with your tank water, randomly successful. It is suggested to plot the error of various concentrations and then to use the plot to make adjustment to the readings.

A similar tack is used to disprove the notion that "nutrients causes algae". This is a popular non sequitur. If someone claims PO4 causes algae and if I add PO4 yet don't get algae - and if I can do this repeatedly with similar results they I can be satisfied that the notion is wrong. If someone needs to see an example of this please check the EI Methods thread in the Tutorial section of the forum. That tank was dosed with between 3X to 5X EI dosing because I wanted there to be no doubt in my mind that nutrients do not cause algae.  

It's a similar story chasing the root cause of diatomic algae. I'll not likely "prove" the cause(s) the blooms, but it's easy to disprove the notion. I mean, good Lord, have you (or any silicate test kit lover) actually added a silicate source to a perfectly stable tank and observed a sudden increase in diatoms? Does your water report state a silicate level? Why does a bloom not appear every water change when a fresh new supply of silicate laden water is added? Why do folks who experience diatoms at tank startup suffer for a few weeks and then observe the diatoms disappear?

These are questions people reading this thread need to think about. . Most important to me is that inexperienced hobbyist or others who suffer difficulties at least try to think critically instead of running to the LFS for some test kit when they experience a problem just because of populist propaganda. We've already laid out the basic principles of plant deficiency analysis, which greatly simplifies the troubleshooting and the resolution techniques.

Cheers,


----------



## dcurzon

id scraped all diatom growth from the glass and gave the plants a bit of a cleanup when I posted this. n 7 days later, and its starting to form on the glass again. (although not a lot of it at present)
I still need to make spraybar v3 (smaller holes) to give a bit more oomph to the water movement, however the rear to front flow does seem better


----------



## Natquascape

Hi @dcurzon - I always get diatoms in a setup - I let it grow and just roughly take some out using a tooth brush - only the major bits, I leave the minor bits. Then...when the tank is cycled I add ottos and amano shrimp - all diatoms gone within 2/3 days. Diatoms are a type of eukaryotic cell that can metabolise silicon/silica. Therefore, it can thrive in a tank containing high concentrations of silica. I have experienced more diatoms when using quartz gravel vs ADA la planta/colorado sand. Hugo Kimishi gravel and sands are decent too. Once we resume to normality, I will get some project students in my lab so run analysis on different brands of sands/substrates to determine their exact composition and report back. Don't hold me to this as I will have to find the time and a pair of hands to do this....far too much teaching to do at work but I will try. I have had diatoms in tanks which I have reported on my YouTube channel (Natquascape). Hope that helps.


----------



## dw1305

Hi all, 


Natquascape said:


> I will get some project students in my lab so run analysis on different brands of sands/substrates to determine their exact composition and report back


I'm very interested in this one. Are we talking about the molybdenum blue method? 

I'll nail my colours to the mast, and say I'd be really surprised if they weren't all 100% SiO2 and pretty much <"insoluble at normal temperatures and pressures">.


Natquascape said:


> ... Diatoms are a type of eukaryotic cell that can metabolise silicon/silica. Therefore, it can thrive in a tank containing high concentrations of silica.


But only if it is in the form of an orthosilicic acid (H4SiO4)?

I've been told that freshwater always contains enough "diatom available silicon" for diatom growth, mainly because they are incredibly efficient at extracting it. My understanding is that once the silica is incorporated into the diatom frustule it is unavailable to any other diatoms, because of its insoluble nature.

cheers Darrel


----------



## jaypeecee

Hi Folks,

I thought it might be a breath of fresh air to admire the sheer fractal beauty of diatoms. To that end, please feast your eyes on the attached piccie. There are lots of photomicrographs of diatoms on the internet. Breathtaking, eh?

JPC


----------



## jaypeecee

dw1305 said:


> Are we talking about the molybdenum blue method?


Hi Darrel (@dw1305)

Would that be the same method used by JBL? The link below shows their 'SiO2' colour chart:









						JBL Silicate Test SiO2
					

Simple and reliable monitoring of water values. Determines silicic acid content when there are diatom problems in tanks




					www.jbl.de
				




JPC


----------



## dw1305

Hi all,


jaypeecee said:


> admire the sheer fractal beauty of diatoms


There is some brilliant <"Victorian slides etc">.


jaypeecee said:


> Would that be the same method used by JBL?


I don't know, if it includes citric acid (to remove PO4---)? it probably is.

I've never actually tested for silicon /silicate, by any means. You have other things to worry about in waste water work and it has never been of interest to any-one I've worked with.

We have had an <"interest in diatoms"> (both in sediment cores and planktonic and benthic diatoms from lakes and streams etc.) because of their use in the <"trophic diatom index">, they are useful for this <"because all freshwater contains diatoms">, including <"really oligotrophic lakes etc">, where other organisms may be in very short supply.

Because the frustules are insoluble they remain intact (which is why you can retrieve them from sediment cores and reconstruct <"the water conditions when they were living">), but they need careful handling (they are basically tiny cups of etched glass)), which means cleaning up with strong acids etc.

cheers Darrel


----------



## jaypeecee

Hi @dw1305 

Thanks for the feedback and the video about Klaus Kemp - absolutely stunning!

JPC


----------



## sparkyweasel

Natquascape said:


> Once we resume to normality, I will get some project students in my lab so run analysis on different brands of sands/substrates to determine their exact composition and report back.


Could you also ask them to test/measure the solubility of the silicon compounds?


----------



## jaypeecee

Natquascape said:


> Once we resume to normality, I will get some project students in my lab so run analysis on different brands of sands/substrates to determine their exact composition and report back.


Hi @Natquascape 

Sounds interesting. I look forward to any updates.

JPC


----------



## dcurzon

I've just changed the lighting today. 
Original rio 125 t5's (2x28w) were at least 8 years old.

I've just replaced with a single 22w Fluval Aquasky 2, which looks much better.  So perhaps the t5's were pretty bad :O


----------



## JoshP12

dcurzon said:


> I've just changed the lighting today.
> Original rio 125 t5's (2x28w) were at least 8 years old.
> 
> I've just replaced with a single 22w Fluval Aquasky 2, which looks much better.  So perhaps the t5's were pretty bad :O


"Better" light, more o2.


----------



## dcurzon

And now finished the spray bar for close to full width.


----------



## dcurzon

some additional plants added, and, local P@H had one lonely little Otto in their tank, so I brought him home and plopped him in.  Kept a careful watch because, well, Tiger Barbs... but a day gone by and I still have an Otto.  They should have more later in the week so I'll keep an eye on this one and if all goes well I'll get him some buddies.


----------



## ceg4048

dcurzon said:


> some additional plants added, and, local P@H had one lonely little Otto in their tank, so I brought him home and plopped him in.  Kept a careful watch because, well, Tiger Barbs... but a day gone by and I still have an Otto.  They should have more later in the week so I'll keep an eye on this one and if all goes well I'll get him some buddies.



Hi dcurzon,
                  I might have missed it, but I thought in one of your earlier post you stated that you actually turned the CO2 down? Have you turned it back up? Also, I'm not seeing a DC in the photo. Have you performed a pH profile to help understand how the CO2 is behaving? We need to know whether the CO2 is sufficient when you turn the lights on. We should have asked for that earlier.

If you float a tiny bit of paper on the surface you should be able to track it's path to give you an idea of how the flow/distribution is.
It also looks like you changed the light, which means you've added another unknown to this equation.

Could you also restate your dosing regimen?

Cheers,


----------



## dcurzon

ceg4048 said:


> Hi dcurzon,
> I might have missed it, but I thought in one of your earlier post you stated that you actually turned the CO2 down? Have you turned it back up? Also, I'm not seeing a DC in the photo. Have you performed a pH profile to help understand how the CO2 is behaving? We need to know whether the CO2 is sufficient when you turn the lights on. We should have asked for that earlier.
> 
> If you float a tiny bit of paper on the surface you should be able to track it's path to give you an idea of how the flow/distribution is.
> It also looks like you changed the light, which means you've added another unknown to this equation.
> 
> Could you also restate your dosing regimen?
> 
> Cheers,


Hi @ceg4048
I had to send my pH checker back to Amazon (waiting on credit refund) as the readings were screwy and it wouldn't let me calibrate... So I've moved the DC from tank #2 to this one, and will be adjusting over the course of the next few days.
I shall order a replacement pH checker and re-profile.

Watching the food when dropping it in, I can see it travel across the top, down the front then a wisp back towards the rear.  By this point the barbs have either got it, or their frenzy is affecting its path anyway.  The stems at the back have a slight movement in the water. Not swaying, more like leaves gently shimmering.

Dosing
I use the same EI mixes across tanks, just adjusting the volume added according to tank size.  Alternate daily macro/micro, although I might miss a day now and then.
Per week, im adding roughly:
NO3: 12.7ppm
PO4: 2ppm
K: 20ppm
Mg: 7.5ppm
Ca: (tap is 36ppm)
Fe: 0.36ppm

You're absolutely right, ive made multiple changes in an attempt to improve things, which to be honest I should know better.


----------



## ceg4048

dcurzon said:


> Watching the food when dropping it in, I can see it travel across the top, down the front then a wisp back towards the rear. By this point the barbs have either got it, or their frenzy is affecting its path anyway. The stems at the back have a slight movement in the water. Not swaying, more like leaves gently shimmering.


Okay, yes, this is what we want to see. If you have the reagent style  pH test kit you can take the measurements while you wait. I'm an advocate of purchasing high quality pH probes, such as the Hanna brand and other top brands. As much as people winge about pH you'd think they would invest in a quality probe and calibration solutions.

In any case, it may take a few weeks of obsessive cleaning and water changes before this issue is resolved, but make best efforts to ensure a high CO2 level at lights on.

Cheers,


----------



## dcurzon

So a 0.6 pH drop, but takes its time to get there. DC is more green than yellow.  I'll wick it up a bit more.


----------



## Wookii

dcurzon said:


> View attachment 164185
> So a 0.6 pH drop, but takes its time to get there. DC is more green than yellow.  I'll wick it up a bit more.



A 0.6 pH drop isn't a problem in and of itself, though 0.8-1.0 would be better. The issue is that you really want to be hitting your minimum pH point _before_ the lights come on, and keeping it there until they go off. I would keep your CO2 running until much later in the photo period, and look to start your CO2 three hours before your lights come on.


----------



## dcurzon

There has definitely been progress!
The solo Otto, having survived and getting along well with the tiger barbs, has been joined by another 4 and a couple of nerites, and the ottos have done a good job of cleaning up the plants.
This week, the diatoms haven't seemed to have returned.  Usually, within a few days of cleaning them off, they are reappearing, but not this time so far.

I seem to have gained a promotion and progressed from ugly diatoms, to green dust algae.  This must be a good thing to move on a step


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## dcurzon

Just a follow up on this..
There are now 5 Otto's and 2 nerites, and they've done a sterling job on cleaning up the plants.  They can't seem to quite keep up with the GDA, however I can say I don't seem to have diatoms now.
So over the course of this particular thread, from long term diatoms to GDA instead (but slower developing than the diatoms were) there's been:  change of light, change of flow, review of co2, clean up crew (couldn't previously add snails due to a loach), some more plants.
Seeing good growth of plants now.

Hate that white sand still. Tempted to change it...

Thanks everyone


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## ceg4048

Hello dcurzon,
                       You can easily add a dark sediment to the top of the sand, or you can gradually take out and replace  small sections at a time once a week or so.
GDA is also CO2 related and is also considered to be one of those "life cycle" types that after a while will go away and become dormant. Very unpredictable. The conventional wisdom is to leave it alone for 3-4 weeks and then remove it all when doing a massive water change. Sometimes it requires a second 3-4 week growth/removal.
The pH drop should be 1 unit, so as mentioned, try to turn the gas on earlier.

Cheers,


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## dcurzon

So a month on from previous post...  Excuse the sideways photo! I've not manually cleaned any algae and it's very much under control. Enough to keep the snail (one died so only one remaining) and 5 Otto's happy, but not enough for me to be able to see it without looking very closely.

And as things now seem to be growing, I'm going to leave the sand, at least for now.

Thanks all


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## dcurzon

So another month has passed, and I still haven't needed to clean the glass at all.  
Some plants have been removed, some added and some moved.
Snails = 0 (just didn't seem to last long in here)
Otto's = 5 (still)
Amano shrimp = 4


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## dcurzon

Just another update, and I still haven't had to clean the tank of any algae . Although I did run out of co2 a short while ago, it still seems to be going ok.

I have no idea what critters are in there, I occasionally see an armano, and not seen any ottos for a while.
Actually, I need to give it a pretty heavy trim as I can't see anything for the plants now


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