# Brown algae/Diatoms



## Badjester1 (3 Aug 2022)

Hi, 
I'm after some advice on what I assume to be diatoms aka brown algae (I know it's not technically an algae.) So my plants were doing absolutely amazing a few weeks ago, yes they are in sand but I use TNC plugs, TNC Complete and they were beautifully green and growing well. Then I had a burst of what I think were pond snails and they started munching on the plants. Mostly the Salvinia and unbelievably annihilated the Salvinia in a matter of days! So I popped 4 assassin's in and they've cleared the pond snails. There's still tiny little snails I believe to be ramshorns that are no bother at all. They're too small to damage plants and seem to eat micro particles of whatever. Anyway when the Salvinia was mostly annihilated I also cut back a lot of the plants as it was getting a bit like a jungle. I also removed damaged leaves from the snails. Still plenty of plants and still heavily planted. However this is where things have started to go wrong. The brown quickly started to cover the highest parts of the tank including leaves like in the photo. attached.

At first I thought too much light what with cutting back etc.  Cut the story short... I've searched and searched online for the best course of action and as usual there seems to be a divide. Some suggest lights minimal or even off. Then some advise (which I actually agree with) that you need the plants to out compete the brown algae/diatoms. They're not going to do that very well if I turn the lights off surely? My lights are only on full for 6 hours a day with and hour sunset and sunrise either side. So at the minute my Aquasky lights are as follows... Red 85% Green 75% Blue 15% and White 80% and that's from listening to Bentley Pascoe on YouTube about settings  for a tank like mine (Fluval Roma 240.) So basically what I'm wanting to ask is this... Am I right to keep the lights like that and just continue to dose the ferts as normal? I assumed the diatoms are more towards the top as they're always going to prefer the highest light source they can get? I have a strong feeling the Salvinia was doing a fantastic job of gobbling up any excess nutrients as they really did cover a lot of the surface. I was always having to take some out. Or am I doing it all wrong and should I be turning lights down or even off? As I previously said if I do that then the plants won't out compete for the nutrients? Any help would be greatly appreciated as I'm tearing my hair out as it's not going away!


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## FrankR (3 Aug 2022)

I'm not an expert, but I think that diatoms go as fast as they come. That takes a week or so. In some cases they persist though.
Natural predators of diatoms are copepods. Otocinclus fish, Amano shrimp and Nerite snails also eat diatoms.


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## GHNelson (3 Aug 2022)

Implement the tutorial below....this will help!
Diatoms will eventually disappear.....do small water changes try not to disturb the substrate.
Ramshorn snails will eat diatoms.








						Using stem plants as a filtering aid at Start Up!
					

The subject of using fast-growing stem plants as part of a filtering aid has cropped up a few times recently. This idea has been around for a long time so not new,....it has benefits especially for a new set - up. I try and cover at least 50% of the water surface minimum.  1. Improves water...



					www.ukaps.org


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## Badjester1 (3 Aug 2022)

FrankR said:


> I'm not an expert, but I think that diatoms go as fast as they come. That takes a week or so. In some cases they persist though.
> Natural predators of diatoms are copepods. Otocinclus fish, Amano shrimp and Nerite snails also eat diatoms.


Thanks for the reply. I'm torn between turning the lights off to see if it helps. Or just leaving them on and adding ferts as normal. Obviously there's an imbalance between lights and ferts which I'm trying to sort. I can look at getting shrimp to help. Just hope it goes because it was looking so good just weeks ago.


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## Badjester1 (3 Aug 2022)

GHNelson said:


> Implement the tutorial below....this will help!
> Diatoms will eventually disappear.....do small water changes try not to disturb the substrate.
> Ramshorn snails will eat diatoms.
> 
> ...


Ok thanks, so my Salvinia is recovering after the snail infestation. I'm hoping once it does it'll out compete the dreaded diatoms.


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## GHNelson (3 Aug 2022)

Hi
Unfortunately pond snails just love some types of floating plants....
You don't need to switch the lights off, reduce the lighting by 50% intensity!


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## GHNelson (3 Aug 2022)

Sure that's Salvinia looks like Amazon Frogbit!
Its always best if members can give as much detail as possible as per sticky below.





						Please read the guidelines for Algae help!
					

Dear Member  Please give as much detail as possible regarding your aquarium set-up, when requiring advice/help! Please upload photographs if possible. Copy and Paste the numbered questions and add your answers next to each!  1. Size of tank in litres. 2. Age of the set - up. 3. Filtration. 4...



					www.ukaps.org


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## Badjester1 (3 Aug 2022)

GHNelson said:


> Hi
> Unfortunately pond snails just love some types of floating plants....
> You don't need to switch the lights off, reduce the lighting by 50% intensity!


Ok thanks I will do that.


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## jaypeecee (3 Aug 2022)

FrankR said:


> I'm not an expert, but I think that diatoms go as fast as they come. That takes a week or so. In some cases they persist though.


Hi @Badjester1 

As @FrankR said above, Diatoms often stop growing after a few weeks. But, if you continue to feed them, they may hang around. Diatoms need silicate (SiO2) in their diet to build their hard outer shell. One source of silicate is tap water. If things don't improve, I'd be tempted to use a JBL SiO2 test kit to see if your tap water is contributing to the problem. Please see below:









						JBL PROAQUATEST SiO2 Silicate
					

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




					www.jbl.de
				




Please keep us updated.

JPC


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## FrankR (3 Aug 2022)

Badjester1 said:


> Thanks for the reply. I'm torn between turning the lights off to see if it helps. Or just leaving them on and adding ferts as normal. Obviously there's an imbalance between lights and ferts which I'm trying to sort. I can look at getting shrimp to help. Just hope it goes because it was looking so good just weeks ago.


I'd suggest you follow @GHNelson 's advice. Diatoms are photosynthetic, so reducing the light to 50% will definitely make their life harder. They do consume silicate though, as @jaypeecee  said.
No need to worry though. They'll go away in a week or so. Be patient.

It would also be helpful if we knew how old is your aquarium, what type of filtration do you use and how much flow does the tank have.


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## _Maq_ (3 Aug 2022)

jaypeecee said:


> Diatoms need silicate (SiO2) in their diet to build their hard outer shell.


That's true, of course. However, I add hydrated silica as a fertilizer occassionaly and it has never led to diatoms appearing in noticeable amount. So I guess some other conditions are more important.


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## jaypeecee (3 Aug 2022)

_Maq_ said:


> That's true, of course. However, I add hydrated silica as a fertilizer occassionaly and it has never led to diatoms appearing in noticeable amount. So I guess some other conditions are more important.


Hi @_Maq_ 

Dependent on the silicate concentration, there may be other important factors. Agreed. Somewhere, here on UKAPS, I think we identified three factors that can contribute to the growth of Diatoms. But, I can't recall in which thread this appeared. I'm just about to shut down for today but use of the Search facility (top RHS) may have the desired result. 

JPC


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## sparkyweasel (4 Aug 2022)

Are we talking about the brown patches on the Amazon Swords? They don't look like diatoms to me, more like damaged leaves. Can you remove the brown patches ny rubbing the leaves?


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## PARAGUAY (4 Aug 2022)

@jaypeecee  think it relates to Clive(ceg) posts were he says we fret too much about rock or sand ,water parameters etc Instead concentrate on  water changes esp. in new set ups and correct distribution of CO2 if using. The use of Ottocinclus ,juvenile SAEs  amano Shrimp as first critters is a good way to see off brown algae. Too much lighting and photoperiod needs addressing. Fast growers and floating plants at start or even add later


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## _Maq_ (4 Aug 2022)

When it comes to diatoms, I'd suggest taking inspiration from nature. Diatoms often appear in early spring (and autumn). Later on, green algae and cyanobacteria regularly prevail, and diatoms disappear. It seems that diatoms quickly proliferate once conditions are favourable, but then just as quickly disappear due to competition of other primary producers (macrophytes, algae, cyanobacteria).


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## FrankR (4 Aug 2022)

This is how I see it.
An aquarium, FW or SW, has to go through two cycles. The first is the nitrogen cycle. The second one is the biome cycle. Both cycles start at the time we set up a tank.
There's plenty of information on the nitrogen cycle. No need to elaborate there. The biome cycle is the most important though in my opinion, because that's how we achieve balance/maturity in our miniatured ecosystems.
It is during that cycle that diatoms, algae and cyanobacteria appear. A tank is like a newly discovered land, where settlers try to establish colonies and dominate.

The best way to keep these "pests" in check is by maintaining a diverse ecosystem where competing organisms exist in balance. This can be achieved by:

Having sufficient flow, effective filtration and good husbandry.
Limiting the introduction of pests in the first place. Clean and rinse new plants, don't add fish-bag water in tank, etc.
Promoting the growth of beneficial bacteria/biofilm to outcompete the pests for resources.
Introducing microorganisms that prey upon these pests, ie. copepods, amphipods, microcustaceans, etc.
Maintaining a CUC, like shrimp, snails, etc.
Adding utilitarian fish, like Otos, Corys, Loaches, etc.

It's worth noting that while diatoms and cyanobacteria can show up in our tanks from thin air, algae has to be introduced into a tank in some way or another.

All the above is based on my limited knowledge and research on aquariums. Like I said, I'm not an expert.
My nano tank's been running for 6 months and it's not balanced yet. This hobby needs patience.


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## _Maq_ (4 Aug 2022)

FrankR said:


> while diatoms and cyanobacteria can show up in our tanks from thin air, algae has to be introduced into a tank in some way or another.


As far as I'm aware, algae too can come from 'thin air'. 
Otherwise, I cannot agree more to what you posted.


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## John q (4 Aug 2022)

FrankR said:


> It's worth noting that while diatoms and cyanobacteria can show up in our tanks from thin air, algae has to be introduced into a tank in some way or another.


The air we breathe containes algal spores, trying to limit these spores entering our tanks is as futile as reducing silicates to prevent diatoms, the next level of wasted reasoning is limiting nutrients to prevent algae. 

@Badjester1  I'm assuming this tank is relatively new? If this is the case then the diatom stage will pass. What happened here? I suspect the reduction in floating plants increased the light levels above what the system could handle, you ended up with a bloom. 

The cure.... rub off any brown deposits, do regular 50% + water changes, reduce the lighting intensity for a while whilst the tank matures  and please for the love of God don't waste your money on SI02 test kits, or silicate removing gizmos... 😀


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## FrankR (4 Aug 2022)

_Maq_ said:


> As far as I'm aware, algae too can come from 'thin air'.
> Otherwise, I cannot agree more to what you posted.


I stand corrected. I thought that algae can be introduced in our tanks by cross contamination. I'm still learning


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## sparkyweasel (4 Aug 2022)

FrankR said:


> I stand corrected. I thought that algae can be introduced in our tanks by cross contamination. I'm still learning


You're right, it can. But _also _from airborne spores.


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## FrankR (4 Aug 2022)

sparkyweasel said:


> You're right, it can. But _also _from airborne spores.


Yes, I think we've established that. 👍

My point is that eradicating one pest, leaves free space for another to thrive. 
So, instead of focusing specifically on how to beat diatoms/cyano/algae, we should focus on how to balance our mini ecosystems by introducing more beneficial organisms.


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## Badjester1 (5 Aug 2022)

jaypeecee said:


> Hi @Badjester1
> 
> As @FrankR said above, Diatoms often stop growing after a few weeks. But, if you continue to feed them, they may hang around. Diatoms need silicate (SiO2) in their diet to build their hard outer shell. One source of silicate is tap water. If things don't improve, I'd be tempted to use a JBL SiO2 test kit to see if your tap water is contributing to the problem. Please see below:
> 
> ...


Great thanks I'll get a test kit. Yeah I've read about the silicates from trying to research about it. The sand I used for substrate is called silicate sand. Unfortunately I learnt that after. It's supposed to be inert but I assume if it's silicate sand it'll leach silicates? If so I have no idea if it'll always leach silicates? Mind you if the sand was the issue I'd of had these diatoms the whole time and I haven't. Definitely a sudden imbalance in something. I bought some phosguard which is arriving tomorrow to help remove silicates. I can only hope it starts to die off soon as the plants were perfect before this. Lights are down by 50% for now.


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## Badjester1 (5 Aug 2022)

FrankR said:


> I'd suggest you follow @GHNelson 's advice. Diatoms are photosynthetic, so reducing the light to 50% will definitely make their life harder. They do consume silicate though, as @jaypeecee  said.
> No need to worry though. They'll go away in a week or so. Be patient.
> 
> It would also be helpful if we knew how old is your aquarium, what type of filtration do you use and how much flow does the tank have.


The tank isn't mature yet. I cycled with ammonia for about 10 weeks. I was taking things very slow to let the plants mature before any fish went in. That was about 6 to 8 weeks ago. Fish have been added slowly but there's 8 red and 8 black phantoms in. 9 Cory's (3 bronze, 3 peppered and 3 panda.) They were all babies so very small when I bought them. I upgraded the filter to the 407 instead of the 307 that came with the tank. That was done about a month ago. I'm still testing water every other day. Never an issue there. Ammonia and nitrites zero. Nitrates are usually zero with the odd time it's 5. Some people seem to think zero is not possible with a cycled tank. In my case it's definitely possible. My tank was cycled and I continued dosing ammonia until just before fish went in after a water change. So it was super cycled lol. I got high nitrates at the start obviously upon the ammonia and nitrite conversion. Then when the plants grew fully the nitrates disappeared. Oh and I had horrendous diatoms while cycling but that was completely expected. Although that was clumps of diatoms. This is more like a coating and darker brown but not black. Anyway that is everything I can remember. Oh and I doubled the ceramic media with the 407.


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## Badjester1 (5 Aug 2022)

sparkyweasel said:


> Are we talking about the brown patches on the Amazon Swords? They don't look like diatoms to me, more like damaged leaves. Can you remove the brown patches ny rubbing the leaves?


Yes it does rub off but I agree it looks different to the fluffy blobs of diatoms I had whilst cycling a few months ago. That's one of the things that threw me as it looks different. However yes it rubs off leaves and off the tops of the ornaments. It takes slightly more vigorous rubbing than the diatoms I had whilst cycling.


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## Badjester1 (5 Aug 2022)

John q said:


> The air we breathe containes algal spores, trying to limit these spores entering our tanks is as futile as reducing silicates to prevent diatoms, the next level of wasted reasoning is limiting nutrients to prevent algae.
> 
> @Badjester1  I'm assuming this tank is relatively new? If this is the case then the diatom stage will pass. What happened here? I suspect the reduction in floating plants increased the light levels above what the system could handle, you ended up with a bloom.
> 
> The cure.... rub off any brown deposits, do regular 50% + water changes, reduce the lighting intensity for a while whilst the tank matures  and please for the love of God don't waste your money on SI02 test kits, or silicate removing gizmos... 😀


Yes it's quite new as it cycled about 6 to 8 weeks ago. The depletion of Salvinia is definitely what I think has done it. They're recovering from what was left and they multiply as quickly as snails! I've already bought phosguard so too late lol. However I'll just be monitoring things closely. Lights are down, frequent water changes. What's confused me is the look of these "diatoms" are very different to the diatoms when I was cycling the tank. They were like hair and big blobs of it. This is more like a coating that does rub off with a bit of effort. Things were going so well! Just hope it starts to die off soon.


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## Badjester1 (5 Aug 2022)

Thanks for the replies folks. I'll update with any changes.


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## jaypeecee (5 Aug 2022)

Badjester1 said:


> Great thanks I'll get a test kit. Yeah I've read about the silicates from trying to research about it. The sand I used for substrate is called silicate sand. Unfortunately I learnt that after. It's supposed to be inert but I assume if it's silicate sand it'll leach silicates?


Hi @Badjester1

Silica sand will not leach significant amounts of silicate. It finds its way into tap water because of what goes on underground. Elevated temperature and pressure causes silicate* to form/dissolve in underground water. And this gets into our water supply. This is well worth a read:






						Silicon (Si) and water
					

Silicon and water: reaction mechanisms, environmental impact and health effects




					www.lenntech.com
				




Hope this helps.

* More accurately, orthosilicic acid

JPC


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## jaypeecee (6 Aug 2022)

_Maq_ said:


> That's true, of course. However, I add hydrated silica as a fertilizer occassionaly and it has never led to diatoms appearing in noticeable amount. So I guess some other conditions are more important.



Hi @_Maq_ 

This paper should be right up your street....!



			https://www.researchgate.net/publication/281773996_Factors_affecting_growth_and_viability_of_natural_diatom_populations_in_the_meso-eutrophic_Rimov_Reservoir_Czech_Republic
		


Results are summarised in Table 1.  The key requirements for growth of Diatoms are - Light, Dissolved O2, Soluble Reactive Phosphorus, Silicate and NO3-N.

JPC


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## jaypeecee (6 Aug 2022)

Hi @_Maq_  & Fellow/Lady Aquarists

Want to learn more? Here's more...



			DiatomBase
		


Happy reading!

JPC


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## jaypeecee (6 Aug 2022)

Hi Everyone,

OK, yet another - just in case you get bored at any stage...






						What are Diatoms? - Diatoms of North America
					






					diatoms.org
				




Ah, coffee time!

JPC


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## PARAGUAY (6 Aug 2022)

Fascinating link that. Almost makes me feel guilty for not wanting them. Maybe set up a tank just for diatoms😂


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## Badjester1 (6 Aug 2022)

I've had a clean up (see pics.) I added some purigen and phosguard which I wanted to add for a while. I know some say yay and some nay but the water is crystal. Had a cut back and tidied up. Lights lowered so will see how it goes. Ordered silicate and phosphate test kits as I'd like to settle my mind on tap water. Have a feeling it's not that but likely increased light due to those damn snails annihilating the Salvinia. That's already recovering well. Fingers crossed I guess. Put some TNC root tabs in as I reckon they'll give the root feeders a boost and hopefully outdo and diatoms. That worked well for me in the first place. Just a waiting game now but happy with the way it looks for now.


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## dw1305 (6 Aug 2022)

Hi all,





Badjester1 said:


> Great thanks I'll get a test kit.  Mind you if the sand was the issue I'd of had these diatoms the whole time and I haven't. Definitely a sudden imbalance in something. I bought some phosguard which is arriving tomorrow to help remove silicates. I can only hope it starts to die off soon as the plants were perfect before this. Lights are down by 50% for now.


Quartz sand is totally insoluble, for all of eternity. Diatoms can only build their frustules from orthosilicic acids in solution.

Phosguard will remove orthophosphate (PO4---) from the water column, and phosphate is one of the three macro nutrients that plants need most of, so it will stop diatoms growing, along with all the plants that you want to grow.

Cheers Darrel


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## Badjester1 (6 Aug 2022)

dw1305 said:


> Hi all,
> Quartz sand is totally insoluble, for all of eternity. Diatoms can only build their frustules from orthosilicic acids in solution.
> 
> Phosguard will remove orthophosphate (PO4---) from the water column, and phosphate is one of the three macro nutrients that plants need most of, so it will stop diatoms growing, along with all the plants that you want to grow.
> ...





dw1305 said:


> Hi all,
> Quartz sand is totally insoluble, for all of eternity. Diatoms can only build their frustules from orthosilicic acids in solution.
> 
> Phosguard will remove orthophosphate (PO4---) from the water column, and phosphate is one of the three macro nutrients that plants need most of, so it will stop diatoms growing, along with all the plants that you want to grow.
> ...


The phosguard isn't going to be permanent. It's there whilst I deal with the issue. It also removes silicates hence why I'm using it. As I said above I've renewed the root tabs as to supply what they need for now. I'm pretty confident that I'd re evaluate if the plants started to show signs of suffering. For the very short term future I'm dealing with the diatoms which haven't shown any signs of appearing back after today. Once the root tabs kick in as per experience the plants will outgrow anything hopefully like when it was under control before the snail munching infestation. I'm obviously not going to sit and watch the plants die off due to lack of phosphates permanently.


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## dw1305 (7 Aug 2022)

Hi all, 


Badjester1 said:


> The phosguard isn't going to be permanent. It's there whilst I deal with the issue. It also removes silicates hence why I'm using it.


Basically there are always enough <"orthosilicic acids">, in solution, to <"support Diatom growth">, we know this because <"diatoms are universal"> anywhere there is liquid water.


Badjester1 said:


> I'm obviously not going to sit and watch the plants die off due to lack of phosphates permanently.


You are good for a while, because PO4--- is <"highly mobile within the plant">. Diatoms can't shuffle nutrients around, so it will reduce their growth. This is  a phosphorus effect, although the same would apply to silicates in solution.

You could try adding some Hornwort (_Ceratophyllum demersum_), it is <"silicified itself">.

cheers Darrel


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## Badjester1 (10 Aug 2022)

So  just an update (kind of) but I do have some further specific questions at the end if anyone can answer them? Firstly I tested my tank and tap water for phosphates and silicates. All the readings were actually around 1ppm. Give or take a slight difference in the shades, the phosphates in the tank and tap water were closest matched to 1ppm and so were the silicates. So that's left me a bit grumpy as it's obviously coming from the tap water (at the moment.) I think someone mentioned RO water or even an RO system. I'm not in the market for either right now purely down to cost. So that rules that out! However after countless asking, searching about brown algae, it's left me with a few questions I'm struggling to really make decisions on.

Some say lights down for brown algae, some say the opposite. I've had my lights down for a few days now and the brown has started to come back only on the tops of things again. Like ornaments, tops of leaves etc. This led me to think in the first place that it wants the maximum light, hence turning the lights down. But even turning the lights down it still appears albeit in very small amounts. I'm starting to really think that turning the lights down may not be the best option? Due to the fact my plants seemed to have stopped growing fantastically like they were a few weeks ago before all this started. I'm thinking more light = more plant growth = no diatoms? Even with the root tabs I put in a few days ago and my TNC complete/Easy carbo, they don't seem to be doing much. This combination used to make the plants go crazy and they looked amazing. So I have been frustratingly playing around with light settings after researching for ages.  

So I guess what I'm asking is the following in regards to lighting...

1. Is it wise to crank the lights up to help the plants outgrow diatoms? 

2. From what I've researched best I can, I put my red light highest, my green second, blue  next and at the minute my white has been at 20% making the tank quite dimly lit. Even the Salvinia doesn't seem to be doing well. Should I turn the white up and does white have much benefit to the plants? Because I was reading that white LED's don't always have any colour spectrum in them? But I have definitely noticed the plants not doing well after dimming the lights. They only get 6 hours a day at the moment anyway due to ambient light.

I'd really appreciate any advice on the lighting as I can't keep tweaking them as I need to find a balance.

Many thanks.


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## Hufsa (10 Aug 2022)

Badjester1 said:


> Due to the fact my plants seemed to have stopped growing fantastically like they were a few weeks ago before all this started.


Put the light where the plants want to have it, dont think about the diatoms.
Dont crank it to 100% if your tank and plants arent ready for that.
Focus on growing your plants well, your diatoms will disappear in due course. They always do.



Badjester1 said:


> 2. From what I've researched best I can, I put my red light highest, my green second, blue  next and at the minute my white has been at 20% making the tank quite dimly lit. Even the Salvinia doesn't seem to be doing well. Should I turn the white up and does white have much benefit to the plants? Because I was reading that white LED's don't always have any colour spectrum in them? But I have definitely noticed the plants not doing well after dimming the lights. They only get 6 hours a day at the moment anyway due to ambient light.


Put the light spectrum to where you think it looks nice. The plants will grow either way, this is the simple and liberating truth. 1% growth increases from a super specific spectrum matters only to those who are producing massive amounts of crops on an industrial scale.



Badjester1 said:


> I'd really appreciate any advice on the lighting as I can't keep tweaking them as I need to find a balance.


I really empathise with your struggle because there are so many conflicting views out there.
K.I.S.S. principle is a good rule of thumb when you find yourself lost in the jungle of advice, at least I find it useful personally 😊


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## Badjester1 (10 Aug 2022)

Hufsa said:


> Put the light where the plants want to have it, dont think about the diatoms.
> Dont crank it to 100% if your tank and plants arent ready for that.
> Focus on growing your plants well, your diatoms will disappear in due course. They always do.
> 
> ...


Thanks for all that and yes I agree with the k.i.s.s lol. I've put the lights up for tomorrow to what they were originally when they were doing great. The lights are Aquasky that came with the Roma 240 tank. I'll bet they're the cheapest set they do so likely 12 watts so even full won't be insane. Although they do look quite bright on full. I'll just have to see how I get on. Not happy with the silicates tests results but hopefully that sorts itself out too.


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## jaypeecee (11 Aug 2022)

Hufsa said:


> I really empathise with your struggle because there are so many conflicting views out there.


Hi @Hufsa 

I always aim to provide advice based on scientific research.  That's why I provided a reference in post #28 above. But, additional information is readily available on the internet specifically dealing with Diatoms and lighting. This is well worth reading:






						Light
					

Diatoms photosynthesize and therefore require light during cultivation. It is about suitable light sources, light intensity and lighting duration.




					www.diatoms.de
				




If anyone on UKAPS has a problem understanding the scientific gobbledy-gook in our hobby, there are generally other members that will do their best to clear up any confusion.

JPC


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## jaypeecee (12 Aug 2022)

Hi Everyone,

For the last couple of days, I've been delving further into the world of diatoms and what makes them tick. I've discovered that diatoms can be said to actually _manipulate_ light. More of that in the next thrilling instalment! And I've learned that there are at least two more elements/ionic compounds on which diatoms depend for growth. These are sulphur and carbonate*. For anyone interested, please take a look at this paper:



			https://www.researchgate.net/publication/358609823_Silica_Sulfur_and_Carbonate_ions_requirement_in_freshwater_diatoms
		


* This would suggest pH of 8 and above

JPC


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## Badjester1 (21 Aug 2022)

Just a final update on this. I mentioned that the brown on the leaves was different to the diatoms I remembered from cycling the tank. They were like big lumps. This is just a brown cover on some leaves. Anyway it can be confirmed as diatoms now, as I got some Otto's and in a day they've done a great job eating it off the ornaments. I actually would have considered Otto's before but for some strange reason I thought Otto's were big fish. Obviously this doesn't deal with the source but I've tested tank and tap water as I said the other week. Both were 1ppm for silicates which isn't ideal. I'm hoping that will go down as it gets cooler. Obviously the initial problem with the pond snails is sorted. The assassins have long cleared those. So plants are recovering especially the Salvinia which the snails nearly ruined the lot. As for light, I've finally concluded that 100% intensity is what works best for my tank. They're not the highest wattage and when I put them back up the plants started to grow again. Having the lights down imo just slowed the plants and left the diatoms to grow. Since I've put them up there's been no extra diatom growth but the plants have gone crackers. All this led me to do a really big clear up, cutting older sword leaves, leaving the new green growth. Funny enough the diatoms only seemed to contaminate older sword leaves? Can't work that one out. So for now the Otto's are the answer and by next spring my tank will be matured and not so new (it's 3 to 4 months at the minute.) I have read diatoms mainly plague newer set ups. Anyway it's kind of under control for now. I'll check silicate readings again in a couple of months and hopefully they've decreased. My plants now that they're growing again should keep them off. I only got 4 Otto's but I'll be picking another 4 up this coming week. They're a must have for me now.


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