Organics Analysis

jeff5614 said:

I hope you all don't mind me jumping into the conversation. I've been following the thread and it's all very interesting and really encouraging to see some "advanced" thinking ( for lack of a better term ) concerning the hobby.

To follow up Yo-han's comment. I recall Tom Barr mentioning something similar when I asked him about limiting nutrient levels to control algae. He said that algae is never limited, their requirements are so low.

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I hope you don't mind me guys jumping in as well but I've been reading with interest and all the information is very much appreciated.

Here is my story on BBA.

I have a tank that had a never ending BBA problem. The tank was dosed with Excel and micros/macros, overfiltered, very good flow. I tried everything written around the forums such positioning the outlets of the filters/powerhead to create circular flow, lowered the light(though the tank had run a year with no algae whatsoever with same lights), increased excel dosing to 3x at some stage, increased all ferts to EI doses(in not so densely planted tank), big weekly water changes, etc... but no luck whatsoever. If anything BBA was happier than the plants. At some stage people were saying the big water changes were the problem but I have another 4 tanks on which I did same large water changes and they had no BBA so I refused to believe(and still don't believe water changes cause fluctuations that trigger algae)
Then of course the advice was I need injected CO2......at which point I gave up as I wasn't going to.

One day after BBA destroyed my plants to the point I no longer cared about them(I have some massive anubias inside and it was the end for them) I gave up. I stopped dosing anything at all. Left it to fend for itself. The only thing I kept doing is 50% weekly water changes as I always used to do that on any tank.
Well, two months the most after that and BBA was gone completely. It died. However the plants suffered severe deficiencies too but free of algae on the leaves which were discoloured for lack of some sort of nutrients. That happened more than 6 months ago. I hadn't dosed anything since yet, but for the record the plants were getting worse as in colouration and quality of growth but still no BBA. So plants are way more resistant to lack of nutrients than BBA the least. At some stage due to laziness I didn't do water changes for a couple of months, still no BBA...Now I want to give the remaining plants a chance and start dosing again but I am afraid to even start in this tank.

I have been able to have deficient tanks with no algae whatsoever at least 3 times and it was always in a plain substrate tank. Dosing the water colum with excel and ferts has caused BBA in two tanks so far(maybe I was doing something wrong but stopping dosing of any kind has cured the BBA in both but would never advise anyone repeating that because the plants will suffer massively too).

Since I switched to soil substrates I have been keeping algae free tanks with very healthy plants with or without water changes, high organic loads, etc... The one thing in common they all have is being overfiltered if that matters, light was never on the low side. In fact the lowest lit tank was the BBA ridden one because I decreased to a minimum at some stage. It seems to me that low amount of ferts in the water colum but nutrients in the soil instead has worked best for me so far. I know the water column is deficient of nutrients because floaters such as salvinia and frogbit eventually refuse to look good and even completely die off but the planted plants have no issues whatsoever at the same time. Hence with anubias, my best results were when I plant the roots in the substrate with the rhizome above of course.

I happen to have a picture of my old nano tank(plain sand) which was on the border of nutritient deficiency although no algae(despite the window sunshine on top of a light period). It was very ugly so my point is not to show aquascaping skills here But the deficiencies in my tanks show up like this and if I leave it, the plant will eventually suffer to the point the leaves will turn completely yellow/r develop big holes/ or fall apart literally/or die but without any algae issues to follow or precede. There's no way I can grow salvinia or frogbit when the tank is in this state, neither can I grow algae at the same time.

The picture below is not the worst scenario I've had of plant deficiencies but as someone else said we avoid taking pictures when tanks aren't at their best.
Mind you the tank was not waterchanged or cleaned for that picture. I took it just before taking the tank apart to put soil in it. The tank was never fertilised with anything at all.



This below on the video is the tank now a year after but with soil substrate, no water changes at all(presuming it has higher organic load than before as I used to do weekly water changes before putting soil) , no fertilisers as usual, same light, same duration, same location of tank and no algae again but no deficient plants. Now I've never cleaned the glass either, so it has some sort of hazy biofilm which the snails and shrimp eat vigorously but it's nothing much for a year to be honest.

Macro shot of the ludwiga

rjordan393 said:

Thanks for sharing your experience. This will lend support to Jeffrey's analysis. Your tank has a very low bioload with no fish and it would be interesting if those using soil with fish and plants have the same experience.

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Yes, the tank above has just shrimp in it.(fed daily)
I have a 5f tank with soil that never had algae in it for the 1.5 year setup so far. I followed Aaron Talbot's mineralization technique for the soil. It has 20-ish platies, 40-ish corydoras and a bushynose pleco and lots of shrimp and 3 kinds of snails I suppose breeding well. It has gone 6-7 months with no water changes. The tank is so clean of algae and the water clear I remember someone asking me if I use purigen. I've never had even oily biofilm which the small tank on the pictures above had at some stage but it dealt with it itself.
The only "algae" I've ever seen in the 5f tank is super minor diatoms once when I added 20 fish at once a year ago. Needless to say substrate was never vacuumed. I honestly don't think organic load in practice is an issue. I think it is to do whether it gets utilized in a tank via the various chemical processes and the likes, or maybe how fast...I don't know but cleaning or no cleaning makes no difference whether the tank is free of algae or algae ridden in my cases.
The tank in which I had persistent BBA does have high organic load(6 clown loaches and a common pleco on top of smaller fish) but the BBA disappeared when I stopped dosing anything, with the bioload remaining the same(probably higher because those platies breed like crazy) So it still doesn't explain why the BBA disappeared when I stopped adding nutrients and excel. The inhibition of BBA was visible when it started receding but I refused to believe my eyes until one day a coulple of months later I couldn't see any at all. Trust me it was such a relief. I'll try helping the plants with a bit of ferts and see how it goes now since algae is gone.
The second tank in which I briefly had BBA while dosing ferts and excel had almost no bioload at the time, it had 6 shimp in it if I am not mistaken that I didn't feed. I was never going to dose ferts and excel on a permanent basis because I didn't want it to affect the shrimp so one weekend I cut out all affected BBA plants which was the dwarf sag covered in it. I didn't dose anymore anything and I've never seen BBA since, it was probably about 2 years ago.

I am not sure if the dissolved organics or organics in the soil are the issue or rather the "filthy" looking tanks when there are visible organic pieces floating in the water.
In one of the tanks in which I had BBA, prior to that I had a strange issue where the water was so dirty looing that plants got covered in debris max a day after good filters clean and water changes. It's like something was causing the organics to be suspended in water and land on the plants and the amount was rather high as if my mechanical filtration failed or the organics were not dissolving/decomposing.
I decided it's due to not enough filtration but too turbulent flow(powerful powerhead adding up to 20x flow) stirring everything, and at some stage, after the BBA had already taken hold I installed another filter which did clear the water for good but did not stop the BBA at the time. Though now this tank is totally clear of it after a year battle and with same organic load.
So it's organics, but it seems to matter where they are exactly, in the water column, covering surfaces of the tank or in the soil/filters decomposing happily away from light availability for algae to take hold.

Hence, I don't use powerheads any more. If I need more flow I add a filter. At least it does something else than blowing around.

So how do you figure this differs for Walstad tanks then, which are able to be stable in stagnant water, or just enough minimal flow to circulate nutrients?

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I am not sure how a stagnant Walstad tank differs to high flow Walstad tank and to other tanks in general. I keep mine with high flow. Maybe the substrate produces nutrients equally all around, plants don't rely on ferts dumped in the water, but mostly on the substrate so flow doesn't matter that much. Either way, it works with high flow for me. It seems to work with low flow or none at all for others.
I know that some reckon carpet plants such as glosso produce enzymes that inhibit compact growth so maybe lack of flow affects plant structure. Some can grow leggy because of that. I was able to grow glosso in my el natural before my tank lights blew up because the tank stayed lightless for a few weeks. It was a slow growth but it was surely carpeting. I got bacopa australis to carpet a small portion too. I don't know if it was because of the flow or the higher light, etc..

Walstad tanks also aren't highly fertilised, some like mine not at all so plants are forced to use any organics, including organic nitrates, etc..
It could be just because one forces the plants to adapt to what's available /produced in the tank rather than spoil them with inorganic ferts so in turn the organics are consumed happily by the plants, at least those in the water column would be rapidly consumed and could be scarce, thus not available to certain algae that loves the organic molecules in nutrients. It's just one guess but it could be something else. Also, as mentioned earlier, Walstad tanks or tanks with similar substrate may just have that better potential to convert the decomposing organics to organic nutrients better than a normal high tech wiped "clean" tank that does it via heavy cleaning and water changes.

Also, as someone else said Walstad tanks are always highly planted to start with. People try to promote "natural growth" and give the relevant environment, pick their plants by what suits the tank, their growth rate, demands, combine plants with different demands to create a balance, etc.. rather than pick plants by what they look like.

I guess what I'm asking is, why do Walstad tanks get away with using substrate decomposition only, but the rest of the hobby seems to feel that decomposition MUST take place only(or mainly) in the filter?

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I don't think high tech keepers promote any decomposition whatsoever. Organics is considered the devil and gets "cleaned" from every surface or device as much as technically possible. This is supposedly to prevent decomposition bacteria to settle in as it competes with the nitrification bacteria for oxygen. That's one of the ideas anyway, along with organics considered a trigger for algae in all type of tanks in most views.

But in a Walstad tank we welcome organics decomposition as it's the main contributor of CO2 and also keeping the tank ticking as organics are kept being produced and not removed via heavy maintenance.

In newly setup tanks(inert substrate, no plants) I happened to over clean my filters sometimes and caused ammonia spikes because of it. So no matter what one says it's possible constant cleaning to be changing the type or amount of certain bacteria. In a balanced tank you want a bit of everything. Even pathogenic organism have enemies in a balanced tank and thus don't overwhelm the fish.

So if you keep disturbing the bacteria, some species of them might as well pack their bags and leave to a better place.
This approach obviously won't do well in a bare bottom tank or tank with unbalanced inert substrate so it all depends on the setup what works best. For some tanks heavy maintenance is essential, for others the opposite could be essential.

Well most heterotrophs are facultative anaerobes, so it depends on the conditions in the tank what exactly function they perform. Depending on the conditions, they can decompose organics in the presence of organics and oxygen, or convert nitrate to nitrite in anaerobic substrate(which is scary), to converting ammonia to nitrite when in the water column and in contact with ammonia and oxygen( bacterial blooms are caused by fast expanding heterotrophic bacteria) They can double up their amount in a couple of hours where autotrophs such as nitrifying bacteria takes 24hrs and more. So they have the potential to take up all surfaces if let free and you end up with nowhere for the nitrifying bacteria to grow. Which eventually leads to water quality issues because heterotrophs are one million times less efficient in converting ammonia to nitrite and they can't really convert nitrite to nitrate but can convert nitrate to nitrite in anaerobic conditions.

So personally, although they are fine in small numbers in the substrate when they decompose organics in the substrate, they are not welcomed either in an anaerobic substrate or in oxygenated water column.

Anyway, with all that said we are already promoting good heterotrophic activity by ensuring they have organics and oxygen inside the substrate. Planting with heavy rooters, having not so deep substrate, a bit of flow reaching it too, detritus from fish and fish food should ensure they have all that they need to be sludge reducers and not something else.
If they don't have oxygen, they won't decompose organics but do something else harmful that happens in anaerobic conditions. If they don't have organics as their nitrogen source they'll be converting ammonia instead if oxygen is present.