12l test tank

[spezzeguti]

Hello from germany
After some discussion with the user pikez i would like to share some results of my little 12 litres test tank with you.


I set it up cause i have some big trouble with stunted tips, deformed and twisted leaves in my 20G tank with EI dosing. Most affected species are from lythraceae family.

Substrate is a small layer of dirt (Compo Sana Blumenerde), capped with old Amazonia. I use RO-water only, remineralized with ca2so4 and epsom salt to about 15ppm Ca and 5ppm Mg. So there's absolutely no KH.
I added 6 gel capsules size 0, fully filled with pure csm+b into the substrate. After about 3 weeks from starting this tank i additionally added some fert sticks containing npk and micros to the substrate (Substral Düngestäbchen für Grünpflanzen).
No ferts to the water column, Co2 just bio, no filtration, nano heater and high light (diy led) for 10 hours.

(Sorry but i haven't found out how to post pics in full size and not just as an attachement)

About 4 weeks, some wc and little trimmings later:

Some gda but easy to handle. No other kind of algae seen yet. Heavy pearling after lights come on and not a single stunted tip.

Water tests have shown that much csm+b leached into the water column. Fe was > 1.5 ppm. But this doesn't cause any stunting, at least in this little tank.

NO3 is about 10 ppm.

PO4 is zero.

I am looking forward to your opinions.

 

[spezzeguti]

Here's my 20G

with some heavy stunted plants:

 

[VaughnH]

Why did you want zero carbonates in the water? That would mean zero KH, which would result in a pretty low pH, and there are some limits to how low you can go in pH without some effect. Did you measure the KH? I suspect that the substrate would add some carbonates, making the KH be above zero.

 

[Pikez]

Why did you want zero carbonates in the water? That would mean zero KH, which would result in a pretty low pH, and there are some limits to how low you can go in pH without some effect. Did you measure the KH? I suspect that the substrate would add some carbonates, making the KH be above zero.

I checked the contents of Compo Sana Blumenerde and it seems to have both NPK and some lime. It is possible that the lime, added as a calcium source, keeps the pH from crashing. I know from offline conversations with OP that the pH is in the mid 5s.

 

[Pikez]

Thanks for sharing all this here, @spezzeguti

This is very similar in scope and results to my new Kill Tank 3, with its rich soil substrate, very little hardness, little to no filtration, and no water column dosing. Based on my results, I am not surprised at all that you're seeing no stunting.

I am pleased that CSM leaking iron into the water column has not caused any issues.

Ultimately, you will need to extrapolate what makes this successful to your larger tank, to solve the problems there. To do that, you may want to increase KH of the test tank to match the bigger tank. 2 KH if I recall. Match the CO2 levels if you can. Light is not an issue. That allows you to concentrate on the form and location of nitrogen and other nutrients.

See if going to an exclusively NH4 form of nitrogen in the larger tank improves things. It may. Lythraceae in my Dutch tank do better with more ammonium than nitrate...but total N is the same.

If N is sequestered in the substrate as ammonia and nitrate, can you, then, dose trace elements in high levels to the water column? Your accidental leaky capsule suggests that these plants CAN endure high trace levels.

My suggestions are to:

1. Standardize KH and CO2 in both tanks.
2. Try dosing N exclusively in ammonium form in the larger tank. (Ammonium Bicarbonate or Urea will work, but the former will add a little KH, so you'll need to take that into account.)
3. Try adding CSM+B into the water column in the small tank. If 1.5 ppm of iron doesn't hurt the plants, then you can probably add a quantified amount in addition to that to push the limits. I had problems when I added 0.6 ppm daily but there were other factors involved.

 

[deepgreen]

Interesting results. I see that one of your affected species is Cuphea. I had Cuphea for several years and had very little problems with it. I use very little macro and micro ferts in the water column and do mainly Osmocote+ root tabs. Some time ago, I tried to see whether increased Fe dosing would lead to stunting, but the results were inconclusive and only some Cuphea stems were affected. I might have changed something else as well. However, I got some GSA recently and wanted to fight them with elevating PO4. I dosed 1.5 ppm PO4 and 5ppm NO3 and 0.01 CSM+B 3x a week for 2 weeks. All of my Cuphea stunted heavily and are only now recovering several weeks later with half the fert dose every second or third week. This is an observation and something else might have changed as well. I wonder whether anybody else had a similar experience. I think Cuphea did not like the high fert treatment in Pikez's tank either. I wonder if you would try to add the same ppm of ferts in your experimental tank for a week whether you would see a stunting effect. I did however not see whether you had Cuphea in your experimental tank.

 

[VaughnH]

I checked the contents of Compo Sana Blumenerde and it seems to have both NPK and some lime. It is possible that the lime, added as a calcium source, keeps the pH from crashing. I know from offline conversations with OP that the pH is in the mid 5s.

As I recall the lowest the pH can go, due to carbonic acid, is around 5.0 or 5.5. So, it may be that that is what makes it possible to do this.

 

[Pikez]

As I recall the lowest the pH can go, due to carbonic acid, is around 5.0 or 5.5. So, it may be that that is what makes it possible to do this.

My soft water Kill Tank is at 4.5 today. Not ideal but everything looks content. But that's not all due to carbonic acid. There is still some buffer left. I will go lower.

 

[slipfinger]

Thank-you for posting this @spezzeguti.

I messaged @Pikez the other day and asked him if he had any experience adding micros direct to the substrate. I figured if someone had experience or new someone that was experimenting with this, Pikez would be the guy to ask. Pikez messaged me back and mentioned he was chatting with some doing exactly this.

@spezzeguti I am very interested in your results and will be following this closely.

Do you think circulation/flow within the tank would make a difference? At some point, do you plan to add some form of circulation/flow to the tank?

 

[Pikez]

Thank-you for posting this @spezzeguti.

I messaged @Pikez the other day and asked him if he had any experience adding micros direct to the substrate. I figured if someone had experience or new someone that was experimenting with this, Pikez would be the guy to ask. Pikez messaged me back and mentioned he was chatting with some doing exactly this.

At least a couple of other people are trying this. No negative experiences to report so far.

I'm encouraged that when some of it leaked into @spezzeguti 's tank that everything grew well.

 

[spezzeguti]

Hello guys, thank you for your replies and your interest.
My Name is Daniel, I forgot to introduce. Sorry for that.

I'll try to answer the questions. Pls be gentle with me for maybe some bad english.

@VaughnH: I chose zero KH just to see if kh has to do something with stunting. And to see if KH is necessary for plant growth.
I still haven't tested for kh, but I will do to confirm.
The pH in the 12l tank is buffered by something, i think the soil and/or the dirt. I took a water sample and put my pH pen from the big tank in it.

@Pikez: it will be hard standardize KH and Co2 in both tanks cause I only use bio co2 in the small tank and inert substrate in the big tank, no soil or dirt.


@deepgreen: I think the 1.5 ppm dose of Po4 had stunted your Cuphea. I made this experience very often in the past. Many species got stunted when I dosed that much po4. But there are many many ppl that don't have problems with high po4.
Some better pics of the only Cuphea stem in the 12l:

@slipfinger: I don't plan to add circulation. I don't see any benefits in this small tank. And i think circulation would have speed up the csmb dissolving to the water column.


Greetz from Lake Müritz
Daniel

 

[deepgreen]

Thank you for your feedback and the useful information.

 

[Pikez]

@spezzeguti , now that you have found a way to grow Lythraceae without stunting (as have I), the thing to do is to introduce one controlled variable into the 12 liter tank at a time. And observe the effects.

Questions I would have if I had your tank:

1. Would adding some carbonate harness cause stunting? If so, at 2KH? 4? 8?
2. Since you suspect adding high phosphate levels cause stunting, why not add just phosphate and see what happens?
3. What would happen if you stopped adding yeast fermentation CO2? Would you see stunting or would everything look the same but just grow much slower? In my small dirt tank, growth is very slow since I don't have CO2...except for Rotala wallichii, which grows fairly quickly even without CO2.
4. What would happen if I added CSM+B at 0.2 ppm Fe three times a week?

 

[spezzeguti]

Hi,

yesterday i did a big wc, trimmed and replanted everything.

Before wc:

I added a small Pantanal a few days ago:

I tested water before wc. NO3 10, PO4 zero, Fe very high - out of test range, KH zero.

After wc (sorry I got to clean the glass better the next time):

News:
I saw the first stunted tips. Not many, just a few. It's very confusing cause I didn't change anything.
Tank ran out of co2 for a day or two, cause bio co2 stopped producing. So I filled in a new mix. It's working well again now, see the dropchecker.
I made a H2o2 treatment against gda. But I don't think this caused the stunting.
Maybe substrate ran out of ammonia?



Now it's time for the first test.
I decided to dose ammonia daily to see if stunting gets worse or disappears.
Not sure how much ppm. What do you think?