[SBS]

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.

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.

 

[SBS]

For the record, here is how a severely suffering hydrophila looks now in a malnourished tank that isn't dosed with ferts anymore and was previously bombarded with BBA. It's a very tough plant that will survive anything but will show all colours under the sun if suffering.

Not the best picture as I was probably taking a pic of the moss but behind the moss is a healthy hydrophila in a 5f soil tank that never had any algae. The hydrophila is no longer there because it grows huge and obstructed my other plants.

 

[niko]

Check out how people deal with BBA in the organics ladden El Natural tanks:

http://www.aquaticplantcentral.com/forumapc/el-natural/93873-bba-el-natural-tanks.html#post697578

 

[Zapins]

Are El Natural tanks actually full of dissolved organics?

I don't think we ever actually tested any to see. It might be that the cap holds all the organics down below and what organics are down there are bound to clay and are not dissolved in the water column. That combined with super low lighting conditions might be enough to prevent it from growing.

 

[niko]

Eh, since when did BBA start caring about light? Since someone told them I guess.

Now the hidden rich soil in an El Natural tank maybe a good point - their water may be void of dissolved organics. But look at the tanks - how often do they get water changes? How often do you remove anything from them (stuff in the water)? Like never. So where does the stuff go, why doesn't it cause algae?

The water in El Natural tank full of plants that breath, eat, spit, cough, sneeze, and reproduce in it has no organics? Joke aside - honestly, I believe that could be so.

Low light slows down algae growth, yes. But if we believe that algae can never be nutrient limited than we must believe that algae is never light limited either. Actually I have an example of that - a tank with just gravel + water in a room that gets illuminated by a puny fluorescent light about 7 hours a day. Tank has no fish, no plants, no filter, no light but it grows algae. So in an El Natural tank algae should slowly but gradually take over despite high or low organics in the water column. Apparently that does not happen very often, if ever. Nutrient limitation or excess is not the direction we need to be looking. If it made sense we would not be sitting here discussing organics but would be enjoying clean, stable tanks every single time without much discussion.

It is not about the chemicals themselves only. It is about interactions also. That is why this fascinating thread has lost some its original interest for me. I found a very good blanket explanation of why BBA shows up and persists in a tank. Interactions running bad.

As we speak I am about to redo that weird tank I mentioned a few times already. Just the other day I removed about 1.5 lbs of cuttings from it. Plants are exploding. Now I start to see new species that had been in there barely alive in the shadows. It is super healthy. Just like the BBA that plagues it. All parameters are perfect, you name it - it is perfect. Even the TDS is now 199 - lower than our tap water because I started to use RO/DI. My hypothesis that BBA is a question of interactions going wrong seems the best so far. Parameter values work for the plants as I saee but help nothing with the understanding why the BBA is very happy too.

 

[Zapins]

Now the hidden rich soil in an El Natural tank maybe a good point - their water may be void of dissolved organics. But look at the tanks - how often do they get water changes? How often do you remove anything from them (stuff in the water)? Like never. So where does the stuff go, why doesn't it cause algae?

It may never actually leave the substrate cap and remain trapped under it. The only way we'd know the answer to this is if we had tank water analyzed. I'd be very interested to see what aquasoil based tanks read at.

Low light slows down algae growth, yes. But if we believe that algae can never be nutrient limited than we must believe that algae is never light limited either.

Algae can definitely be nutrient limited just like plants. I think the reason we don't recognize nutrient deficiencies in algae like we do in plants is because it is all filamentous or microscopic. This is the same reason why grass like plants and thin leafed plants make terrible nutrient deficiency indicators - because the thin leaves don't have enough space to properly show the visual deficiency symptoms that broad leaf plants do. It isn't that algae can never become deficient in a nutrient.

In fact, I'd guess that algae is more easily nutrient limited than plants are. Nutrients are all taken up by transporters in the cell walls. Many of these transporters are likely very similar if not exactly the same for plants and algae. Meaning they can both take up nutrients if the concentration of a given nutrient is above some tiny value (for this example say 0.0001 ppm). So if nutrient levels in the water ever drop below 0.0001 ppm then plants and algae get nutrient deficiencies as long as they cannot get nutrients from some other source.

So one possible answer to why soil based tanks (El natural, aquasoil, high tech soil) have very little algae is that the water column becomes devoid of nutrients (below our arbitrary 0.0001 ppm value) which starves algae but not plants who have roots which give them access to unlimited nutrients. This idea makes a lot of sense because plants absorb nutrients from the water column by using their leaves and stems. This may help deplete water column nutrients quickly and prevent algae from feeding. Therefore, you'd expect any algae in soil based tanks to be near or in the substrate and that is typically what you see (think about the green tinge white sand substrates develop over time).

 

[niko]

Why would I post the following here? I have no clue.

http://blogs.hbr.org/2014/05/a-social-brain-is-a-smarter-brain

 

[Skizhx]

Regarding organics in El Natural. After a couple years of being established without cleaning or maintenance your substrate cap will gradually accumulate a mulm cap. Still no algae problems.

My old ecology prof actually grew plants in inert gravel saturated with mulm collected from other tanks and accumulated.

Maybe the cap locking in the organics has something to do with it initially in the tank's younger stages... But I don't think that's all there is to it.

 

[SBS]

Is mulm, when it becomes mulm, actually organics releaser? I thought mulm is the product of organics in a way but it doesn't contribute to the organics load.
When I setup my small tank I loaded the soil with mulm from several tanks, like lots of it, no algae outbreaks afterwards but I never thought mulm releases any nitrogen products such as organics do. I have actually used mulm to raise cory fry without consequences. I covered them in mulm to the point I could not see a thing.

 

[Skizhx]

No, I wouldn't imagine fully decomposed mulm product releasing organics. But the process of allowing it to accumulate (in other words, letting a layer of organics sit in the tank long enough to fully decompose on a regular basis without removal) would. I guess the real question is how much of it is actually accumulating, since we typically don't do water changes.

 

[niko]

I have 3/4" of mulm in one of my tanks. Tank is low light, no CO2. Algae is zero, fish overload, minimal flow. At least 50% of the tank is occupied by plants - mainly moss, but there are about 10 other species of plants in there. The TDS in that tank is the highest of all of my tanks - 550, but it was 600 when I started to add RO water to it about 2 weeks ago. Minimal water changes. Plants are starving.

How is it that this tank stays algae free? Maybe a tank like that is a good candidate to send a sample to Jeffy to test for organics. Everything says it should be overloaded with them.

 

[Yo-han]

Perhaps the mulm adsorbs (not absorb) the molecules that trigger BBA (or algae in general). Mulm has quite a high CEC and binds lots of stuff. Maybe it's not high organics in general, but just a single (group of) molecule(s) that triggers them. Perhaps this molecule is often present in tanks with high organics, but not always.

 

[niko]

Mulm that can be stirred and 2-3 minutes later settles and leaves the water completely clear is different from mulm that stays suspended for hours and makes the water murky. I assume that the first kind is mineralized. And I assume that that kind of mulm has completely different properties and impact. That is the stuff that you can syphon from your tank and add to a brand new tank and have instant cycling.

Actually tanks that have been started that way run perfectly from day 1. I have done that maybe 2 or 3 times. One of them has been running 100% problem free for 5 years now! Another tank was setup during one of our club meetings. We setup the tank at a school and we dumped some mulm in it. Could have been the dirt we squeezed from a filter. The tank instantly turned into a box of mud. Then we stood in front of it, smiled, took a picture. And everybody said we should have taken the picture before dirtying up the tank, haha. That was pretty funny, but what was not funny was what had happened to the tank 2 months later (I think, no less than two months for sure). 2+ months later it had 2 angelfish in it - too crowded for its size (29 gallons). The kids loved the tank and the fish. The fish had names and all. The water was crystal clear. They told me that it was super clean like that from day 2 and never gets dirty. Now that I find funny indeed!

 

[Skizhx]

Ok, so... Let's assume organics are the culprit... What have we learned? What do we change?

Don't overfeed? Keep a sensible bioload? Don't grow your plants at pointlessly fast rates just because you can? Facilitate fast and healthy decomposition? Use a good substrate to bind compounds from the water?

 

[SBS]

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.

 

[Skizhx]

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.

Makes sense to me.

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?

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?

For someone who's done a lot more stagnant tanks than filtered tanks, it sometimes looks like people are forgetting what substrate decomposition can do for a substrate, and the many ecological roles it plays which support the plants and drive ecosystems (it seems we have a lot of mulm fans here already), and are instead trying everything they can to pull all the waste off the bottom of their tank to trap it in their filter (Why? So it can be removed easily to prevent decomposition?). Then they wonder why there's bits of waste floating around in their tank that never seem to decompose properly...

From my perspective it seems a bit counter-intuitive... Inhibiting a natural plant-supporting process by separating it far away from the plants with the notion of strengthening a miniature ecosystem that's intended to support plants.

 

[krisw]

This recent discussion takes me back 10 years to when we debated whether or not to add peat moss under the substrate or not. A quick googling bring up a very similar discussion.... In my fishroom, the only tanks that stay mostly BBA free are brand new Aquasoil tanks (for about 3-6 months, and then BBA creeps), and my farm tank that has wormcastings capped with old Aquasoil, running 5+ years as such.

Are any of you using peat moss/mulm under the more inert substrates like flourite, eco-complete, etc and noticing less BBA in those tanks?

 

[SBS]

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?

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?

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.

 

[Yo-han]

So would it be better to not vacuum the tank substrate? Or only the top layer?

I don't believe organics in general to be bad. Aqua soil is loaded with it, but certain organics must be triggering algae when BBA pops up when I increase my feeding.

 

[Skizhx]

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.

Well said.

Rid our tanks of ecologically essential processes, control every parameter, make our system unflexible and sterile. That's how to achieve the stability and beauty of nature!

Lots of literature out there cites resource competition in nutrient-limited habitats and allelopathy as the mechanisms that plant communities use to force algae out of their habitats in nature.

It was over 30 years ago (at least that's the oldest journal article I have that explicitly mentions the transition) that aquatic plant cultivators began adopting the practice of using natural substrates to replace water fertilzation because they realized they could largely eliminate algal blooms and increase the stability in their cultures. So... Why exactly did the hobby revert back to a dependence on water column ferts?

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.

Also well said. To each their own. It all depends on what kind of tank you feel like running I guess. I'm also not implying that it's all as simple as switching to a soil substrate or anything. I'm just more doubtful of the sources and experiments that provided the data we use as foundations than anything else.

I'm also somewhat bothered by how readily we accept information from anyone who seems vaguely qualified. A lot of notions in this hobby just seem bizarre and misguided with terrible evidence/data backing it up. As far as I've been able to experiment on my own, some of them seem downright false.

It's nice to see fans of mulm and natural substrates though!