So what is organic wastes?

[roadmaster]

Can smell when canister (s) have been neglected too long and waste collecting there is going/gone rotten.(stinks)
Properly maintained, the media inside smell's like wet dirt = good.
I do not run pre filter's on my community tank,(Turquoise rainbows,celebs rainbows,swordtails) so a few cherry shrimps that live therein, are always found inside the filters when I drain the filter's into bucket for back flushing the eheim 2217's.
They seem to be alive and well living in the canister's, but as mentioned,,I clean the canister's every four week's.
Used HOB aquaclear 110's for year's and media in these was exposed to far more O2 than that found inside sealed canister's.(never rotten smell)
I was one of those who believed that a canister only needed cleaned every few month's, but my fishes seemed to suggest that this was not true.
I keep,breed,trade, longfinned albino Bristlenose in another tank, and this tank needs filter maint nearly every two week's 55 gal with Rena XP3 and aquaclear 802 power head for added water movement near the surface.
Tank holds 1 old Royal pleco,two female and one male Bristlenose,six panda corydoras,and two or three dozen fancy guppies along with gobs of cherry shrimps.(pre filter on intake of this tank)
All tanks get 50 % water change each week.
Maybe twice weekly when baby bristlenose swarms are produced.
Perhaps I keep more fishes than other's so waste is more than other's might see.
Have had nothing but good result's with afore mentioned maint.

 

[Bart Hazes]

In our hobby there are many things we don't know but that has never slowed down the stream of opinions as to what is going on and how we should respond. We do that in science and call them hypotheses but an important part is to remember that a hypothesis/opinion is not the answer, just one possible answer. There is a risk that an ad-hoc explanation, especially if repeated again and again in books or internet, becomes the gospel truth and stymies further thought or experimentation on the subject. So kudos for waking us up with this thread.

I consider this thread to be one such topic where the observations are clear but the causes are not. Fortunately, you don't always need to know the details to take appropriate action, but it would be satisfying if we could figure it out someday. To me it is just one symptom of the 'closed system syndrome' where imbalance between things entering and leaving the tank accumulate over time to cause problems. For sensitive fish, or plants, this just shows up earlier. The solution, even if we don't quite know what is the culprit, is to make the system less closed by doing water changes. You can do this on a regular 'preemptive' schedule or you can have some sensitive fish and plants and use them as canaries in the coal mine.

 

[AverageWhiteBloke]

hypothesis/opinion is not the answer, just one possible answer. There is a risk that an ad-hoc explanation, especially if repeated again and again in books or internet, becomes the gospel truth and stymies further thought or experimentation on the subject.

So true, space weekend was on TV this week. So many references to water being brought to earth riding on the back of Kuiper Belt comets, something that most scientists have stuck to for decades. Following the Rosetta mission it's now seen as highly unlikely as the water on these comets is of a different make up of the water found in our oceans.

You can do this on a regular 'preemptive' schedule or you can have some sensitive fish and plants and use them as canaries in the coal mine.

I find with a lot of problems people tend to use the flight and fight mechanism, they see something that sounds like the same problem as they are having and assume they have the same problem and start changing things that didn't need changing. Doesn't help when we are dealing with invisible issues and unreliable means of testing. The mantra has always been listen to the plants but the problem with that is some people don't know what the plant should look like. Some plants even in good health have different colour veins and display different leaf types under certain conditions, that's not to say the plant isn't healthy but most will question iron and magnesium and are they getting enough. If the plant isn't dissolving then it's in relatively good health. We often see plants in showroom condition under optimum conditions but if you check out youtube videos with plants in their natural habitat you will see some do have brown edges or holes in leaves and weird shaped growth, do we question the river its living in?

Coming back to canaries, I've found that adding Duck Weed will tell me far more than anything else I can test or second guess thanks to @dw1305 for some understandable explanations that even an idiot like me can get my head around. If these are doing well even if some other plant isn't at the moment you can pretty much bet you're on the right track and keeping things the way they are the plant that wasn't doing well will often recover over time. I'm also quite shocked after some recent experiences on how little extra fertiliser plants need to thrive in a well established tank.

Regardless of what algae inducing crap is in there it needs to come out and the more wc's the along with good filter maintenance the better. I've found that regardless of what I was dosing the prior will do more for your tank than messing with any nutrients, all you end up doing when messing with your mixes and ratios is masking the underlying issue which is a dirty system. I now dose half of what I used to in the same aquarium with same lighting, co2 etc but increasing cleanliness has made the tank look 10x the tank it was when dosing double the amount of ferts but leaving filter and pipe cleaning until I had to convincing myself that my filter was a nitrate making machine and plants love nitrate. 😀

I think clarification was needed as too much credence is given and discussed about "re-setting" the tank when dosing EI without mentioning all the other stuff that's in there. Re-setting the tank should take a back seat to the real reason for changing the water, too much emphasis on plenty of co2 and unlimited ferts when it should be on very clean well oxygenated water flowing through clean filter media. Would be nice to say the reason behind the water change is to remove xyz and forget about salt build up which is the least of our worries. In a world of invisible enemies people want something tangible that they can see or feel is working, hence DWI worked for me I guess.

After all these years I still don't really know what's in there, all I know is it needs to come out. I always hark back to a book I read must be 25 years ago which was only a simple thin beginners guide to fishkeeping and two things that I read in there that always stick in my mind were "the solution to pollution is dilution" and "doing a water change is the same as opening a window to let fresh air in" I think when I got into planted tanks that because some of the chemicals I was warned about then were seen as vital now I sort of lost track of my way but now I see it as more important than ever, I got lazy and thought the plants were doing the work which is sort of true but they're only helping.

 

[dw1305]

Hi all,

Can smell when canister (s) have been neglected too long and waste collecting there is going/gone rotten.(stinks). Properly maintained, the media inside smell's like wet dirt = good.

That is it. The wet earth smell is the aerobic micro-organisms.

If you have rotten smelling media then it has become anaerobic and you can smell a mix of ammonia (NH3) and, if things are really bad, hydrogen sulphide (H2S). There is a fuller description in <"Winogradsky column">.

so a few cherry shrimps that live therein, are always found inside the filters when I drain the filter's into bucket for back flushing the eheim 2217's. They seem to be alive and well living in the canister's, but as mentioned,,I clean the canister's every four week's.

I've got Asellus, snails and Black-worm in mine and they do really well.

There is a risk that an ad-hoc explanation, especially if repeated again and again in books or internet, becomes the gospel truth and stymies further thought or experimentation on the subject. So kudos for waking us up with this thread.

That is really the problem with discussion of biological filtration on forums, lots of people hold "faith" positions and there isn't a willingness to engage with new research or new ideas.

I think I'm right, but I don't have any empirical evidence of suitable scientific rigor. The problem with ecology (and that is really what we are talking about) is that there are a lot of "grey" areas, with a huge number of variables. You can build a model of what you think is happening, but your model is only as good as the data you put in.

Doesn't help when we are dealing with invisible issues and unreliable means of testing. The mantra has always been listen to the plants but the problem with that is some people don't know what the plant should look like. Some plants even in good health have different colour veins and display different leaf types under certain conditions, that's not to say the plant isn't healthy but most will question iron and magnesium and are they getting enough. If the plant isn't dissolving then it's in relatively good health.

I just want some growth out of my plants, I don't really want them growing optimally, I just want them growing. If the growth rates of the non-CO2 limited plants suddenly increase I know that I have more of the limiting nutrient, probably usually nitrogen in my tanks.

To me it is just one symptom of the 'closed system syndrome' where imbalance between things entering and leaving the tank accumulate over time to cause problems. For sensitive fish, or plants, this just shows up earlier. The solution, even if we don't quite know what is the culprit, is to make the system less closed by doing water changes. You can do this on a regular 'preemptive' schedule or you can have some sensitive fish and plants and use them as canaries in the coal mine.

The canary aspect is covered to some degree in <"Do I need to cycle....">, which has many of the same posters as this thread.

Coming back to canaries, I've found that adding Duck Weed will tell me far more than anything else I can test or second guess thanks to @dw1305.

I want people to use floating plants, and the "Duckweed Index", not only because it massages my ego, but because I'm sure that it makes tank management easier.

This works on the assumption you have sufficient PAR, but it is a simple set of rules, if your "Duckweed" (usually Limnobium for me, although Lemna minor would be more responsive to deficiencies of non-mobile nutrients like iron (Fe), because of its quicker potential growth rate) is green and growing (however slowly) just carry on as normal. If it turns yellow, or stops dividing, add a small amount of fertiliser. If I add potassium nitrate (KNO3) that covers the two macro-nutrients that plants need most of. If you don't get a fairly instant greening (they are mobile within the plant), you could add all the other nutrients one at a time, but I just add a complete fertiliser at that point.

I don't need to know which the limiting nutrient is, I just need to raise the level of it.

After all these years I still don't really know what's in there, all I know is it needs to come out.

I don't know either, and I'm not sure anybody else knows. Even if we just look at ions, I used conductivity is a base-line datum, because it is easy to measure and is a linear measurement across a whole range of water types, but the problem is that every-bodies baseline will be different.

For me I know that about 80 - 150 microS in the tanks is the range I want, but I don't know what those constituent ions are. If I used our hard tap water, rather than rain-water, in the tanks I would need to add ~400microS to take into account the carbonate hardness.

cheers Darrel

 

[Bart Hazes]

... text removed ...
I want people to use floating plants, and the "Duckweed Index", not only because it massages my ego, but because I'm sure that it makes tank management easier.

This works on the assumption you have sufficient PAR, but it is a simple set of rules, if your "Duckweed" (usually Limnobium for me, although Lemna minor would be more responsive to deficiencies of non-mobile nutrients like iron (Fe), because of its quicker potential growth rate) is green and growing (however slowly) just carry on as normal. If it turns yellow, or stops dividing, add a small amount of fertiliser.
... text removed ...

cheers Darrel

I tend to harvest floaters if the Limnobium turns yellow to better match the plant biomass to the waste production of the fauna in the tank. Fertilizer would work to green the floaters but I have too many already so I (and my composting worms) am always happy if it time to harvest.

 

[Soilwork]

Great discussion. I have to say that I stopped using a canister filter opting for a surface skimmer to tackle the biofilm. I figured my substrate would take care of the nitrification side of things.

Finally after Cyanobacteria showed up (again) I decided enough was enough and began to change water and lots of it. I installed a canister filter with spraybar and for the first time in a while a have new growth from my plant. Further more the cyano is residing and biofilm takes much longer to form. My thoughts would be cyano contribute heavily to the biofilm. My substrate was very dirty on top and the compounds within would surely be contributing too.

The tank in the attached picture suffered from every algae imaginable for the first 6 months then I decided to get my act together. Again I purchased a spray bar and a second internal filter and began to change water. The biofilm disappeared and the surface was almost mirror like and he plants exploded. The substrate was soil. I wasn't using micro ferts just NPK no calcium or magnesium.

My only thoughts are if oxygen is low for microorganisms would this not become apparent sooner via larger organisms like fish, snails and shrimp? Secondly when I did eventually tear the tank down the substrate smell was horrendous yet the health of the plants is undeniable so I would say that these smelly processes may be beneficial if not necessary in a well established substrate and tank.

 

[dw1305]

Hi all,

Secondly when I did eventually tear the tank down the substrate smell was horrendous yet the health of the plants is undeniable so I would say that these smelly processes may be beneficial if not necessary in a well established substrate and tank.

Yes, it is fine in the substrate, essential plant nutrients like iron (Fe++) will become available in the anaerobic zones with negative REDOX values.

You will always get a zonation of REDOX values in a tank with rooted plants, and near plant roots (and the substrate surface) you will get <"zones of fluctuating REDOX">, which maybe particularly important for plant nutrient availability.

You can also get a similar zonation in a mature <"Hamburg Matten Filter">, or even a wet and dry trickle filter.
http://www.swisstropicals.com/library/aquarium-biofiltration/
The difference between substrate, matten filter and a canister filter is that in the canister filter you have a finite amount of oxygen, whereas the substrate and HMF filter plate have access to oxygen from the water column.

Trickle filters have the added advantage of having access to atmospheric oxygen, meaning that you can use them to treat liquid wastes with a huge BOD (this is how the older style sewage treatment beds work).

cheers Darrel

 

[dan4x4]

Reading this thread is really interesting. Thanks for everybody's input.

 

[jaypeecee]

Hi Folks,

What an interesting thread! I have a few questions:

[1] Should we use liquid (biological) organic waste removers to help break down organic waste on the substrate?

[2] Should we use organic waste removers inside the filter (e.g. Purigen, Renew) to, for example, reduce the frequency of water changes?

[3] Do adsorbing organic waste removers inside the filter release compounds (e.g. nitrates, phosphates) back into the water?

[4] Do plants suffer if dissolved organic compounds (DOCs) are removed from the water column? (I have in mind ferrous gluconate).

That'll do for the moment!

JPC

 

[jaypeecee]

On top of that there appears to be a lot of people advocating not vacuuming the substrate.

Isn't the thinking there that heterotrophic bacteria in the substrate may get released into the water column and become dominant over autotrophic nitrifying bacteria in the filtration system? As I understand it, heterotrophic bacteria multiply rapidly in stark contrast to autotrophic bacteria. The trick is to vacuum only the surface of the substrate - easier said than done if you're using sand!

JPC

 

[jaypeecee]

Hi Folks,

Anyone got any answers to the questions that I posed above?

P-l-e-a-s-e!

JPC

 

[jaypeecee]

The easiest ways of getting a lot of oxygen in the water are to have growing plants and a very large gas exchange area to water volume ratio.

Hi Darrel,

Whilst the gas exchange area to water volume is essentially constant for a given tank, the oxygen contribution of growing plants surely only applies during the day. At night, the situation reverses and plants absorb oxygen from the water. But the breaking down of organic waste presumably takes place 24/7. So, dissolved oxygen will reduce overnight.

JPC

 

[sparkyweasel]

Isn't the thinking there that heterotrophic bacteria in the substrate may get released into the water column and become dominant over autotrophic nitrifying bacteria in the filtration system? As I understand it, heterotrophic bacteria multiply rapidly in stark contrast to autotrophic bacteria. The trick is to vacuum only the surface of the substrate - easier said than done if you're using sand!

JPC

Surely any bacteria etc disturbed would be syphoned out as you vacuum? But mostly they would stay attached to the substrate. Bacteria can stick to the sand in a fluidised bed filter, so I don't think a gravel vac would loosen many of them.

 

[dw1305]

Hi all,

[1] Should we use liquid (biological) organic waste removers to help break down organic waste on the substrate?

You don't need anything, particularly if you have plants rooted in the substrate, roots are <"leaky structures">. You can get "sludge buster" type bombs and treatments, they are designed for use septic tanks, but they have a following amongst people who keep <"ponds etc.">. I can't imagine any use for them in the planted aquarium.

[2] Should we use organic waste removers inside the filter (e.g. Purigen, Renew) to, for example, reduce the frequency of water changes?

If you have enough oxygen you should get <"complete oxidation">. I'm not a fan of chemical media and I like water changes.

Do adsorbing organic waste removers inside the filter release compounds (e.g. nitrates, phosphates) back into the water?

Yes, they could do if they, but it would be more likely that they would just stop being active. Ion exchange resins definitely could begin to exchange (formerly bound) ions back into the tap water, but ion exchange depends on both the position of the ion on the <"lyotropic series">, and their concentration.

Do plants suffer if dissolved organic compounds (DOCs) are removed from the water column? (I have in mind ferrous gluconate).

It would only really be chelated compounds that were retained, have a look at <"Fe EDDHA">.

Isn't the thinking there that heterotrophic bacteria in the substrate may get released into the water column and become dominant over autotrophic nitrifying bacteria in the filtration system? As I understand it, heterotrophic bacteria multiply rapidly in stark contrast to autotrophic bacteria. The trick is to vacuum only the surface of the substrate - easier said than done if you're using sand!

I'd have to say I'm sceptical, the microbial assemblage will vary dependent on the amount of food. If you have a <"bacterial bloom"> it is because you have the "low hanging fruits" of easily available sugars and proteins. I don't vacuum my substrate, but I do occasionally syphon dead leaves etc from the sand surface. The possibility of organic waste blocking the filter is the reasons that I only want ammonia and oxygen entering the filter.

Whilst the gas exchange area to water volume is essentially constant for a given tank, the oxygen contribution of growing plants surely only applies during the day.

Yes and no. In a non-planted tank it is always night. This is because plants are massively contributors to net oxygenation. One molecule of oxygen is evolved for every molecule of CO2 absorbed, and plants grew. That growth is the carbon that ends up as plant tissue, rather than CO2.

The other reason is that the <"plants internal spaces"> are saturated with oxygen at the end of the photo-period, and it is largely this oxygen that the plant utilises at night.

At night, the situation reverses and plants absorb oxygen from the water. But the breaking down of organic waste presumably takes place 24/7. So, dissolved oxygen will reduce overnight.

It will. If you had a tall tank with a large bio-load and relatively small gas exchange surface you might have issues at night, even with plants and a large capacity canister filter.

cheers Darrel

 

[jaypeecee]

Surely any bacteria etc disturbed would be syphoned out as you vacuum? But mostly they would stay attached to the substrate. Bacteria can stick to the sand in a fluidised bed filter, so I don't think a gravel vac would loosen many of them.

Hi,

I agree with everything that you have said. Someone on a well-respected forum wrote an extensive article suggesting that it was wrong to disturb the substrate and to use bacterial supplements to help break down organic waste. And this was because of concern that heterotrophic bacteria would take over. When I have a moment (!), I will try to find that article. I sent a PM to that person challenging them to support what was being said but never got a reply.

JPC

 

[jaypeecee]

Hi Darrel,

I am very grateful for your comprehensive reply - thank you!

You have answered all my questions and there is one gem of information in your reply where you said:

"The other reason is that the <"plants internal spaces"> are saturated with oxygen at the end of the photo-period, and it is largely this oxygen that the plant utilises at night".

I was not aware of this.

With reference to my question [2], my understanding of Seachem Renew is that its mode of action is more akin to a molecular sieve than an ion exchange resin. That's what Seachem told me when I contacted their Technical Support team recently. But my background is in physics and the term 'molecular sieve' was new to me.

Thanks again.

JPC

 

[Edvet]

more akin to a molecular sieve than an ion exchange resin.

Not sure that isn't just "big words" to sell a product, more then an actual description.
Talking about a molecular sieve i think of semipermeabele membranes (RO), not something sitting in a solution. Maybe the molecule exchange in a biological film, as in all our filtres happens, is what happens.

 

[dw1305]

Hi all,

my understanding of Seachem Renew is that its mode of action is more akin to a molecular sieve than an ion exchange resin. That's what Seachem told me when I contacted their Technical Support team recently. But my background is in physics and the term 'molecular sieve' was new to me.

I'd be honest and say that this is the first time I've come upon <"Seachem Renew">.

The "molecular sieve" bit means that it trapping molecules with a certain size This could be an entirely physical process (like if you used a diatom filter) or by chemical means (like Purigen) or a combination of both. By the look of the description it retains molecules that are bigger than those trapped by Activated Carbon or Purigen. I can't tell you exactly what Renew is, it looks to be another rock of <"volcanic origin">.

Not sure that isn't just "big words" to sell a product, more then an actual description.

It looks like another Seachem classic, they don't actually tell you what it contains or how it works. The phosphate bit is just a total red herring, you have to admire their chutzpah. It isn't a product that is going to have any effect of phosphate levels. PO4--- is an ion, and orders of magnitude smaller than the compounds this will filter out, but you set up a paper tiger and then you demolish it.

I'm going to have a go:

"Darrel's Amazon Frogbit will protect you against werewolves, other floating plants may be attractive to werewolves, but this will never be an issue with Darrel's Amazon Frogbit".

cheers Darrel

 

[jaypeecee]

Hi Darrel,

I did manage to find out about molecular sieves. Wikipedia described them as follows:

https://en.wikipedia.org/wiki/Molecular_sieve

I guess that the dissolved organics from organic waste are much larger than water molecules. So, water freely passes through the Seachem Renew and dissolved organics are retained. That being the case, would that mean that nitrifying and other bacteria can't get to work on these tasty morsels? If they can, then the organic waste would be broken down inside the filter and that would seem to be counterproductive, wouldn't it? Or maybe not.

To be fair to Seachem (or, indeed, any other manufacturer), I can understand them not wanting to say what Renew contains. Proprietary information, trade secrets and all that. I like your advertising slogan for Darrel's Amazon Frogbit. Excellent!

JPC

 

[Zeus.]

Proprietary information, trade secrets and all that.

Which translates to trade secrets, profit, failure to give the facts and data to support their claim, holding back science. "Data on file" is what we see company's in my field use to hide the evidence of their claims for their products, which to me means weak unsubstantial results with resulting graphs without fields