Can it be too much??

[incubus3x3x3]

Hi guys,

From your experience is it possible, at some point, to have too much CO2 for plants?

I have GH=6, kh=4 and pH=5.7 so, theoretically i have 239.43ppm CO2. I know, i know... I shouldn't take into consideration that table, and I don't. But still...

I'm asking because despite the things looks fine on paper, plants are not happy. The CO2 seems to be enough (if I go lower than that red cherrys are obviously stressed... like... dead ) enough nutrients (30ppm NO3, 3ppm PO4, 50ml JBL micro solution which is twice the recomended dose per week... and so on), good water flow (one canister and 2 powerheads). The water volume is 100 liters or about 27 gallons. I'm adding Mg2+ (from MgSO4) and besides, JBL claims that them micro fert contains Mg as well.

The actual simptoms are: Pogostemon stellatus - melting, Pogostemon helferi - melting, Limnophila aromatica - grows very slow, all other plants are surviving but none of them are growing at the speed I know they can, and no one is pearling anymore.

So... I know the CO2 is not low. I know the flow is not insufficient. I know the nutrients are fine (full E.I.) + micros... I can't think of anything else
than maybe... something is too much.

From your experience, is this possible? Maybe too much CO2? Maybe too much water flow?

Any opinion or suggestion is welcome.

Many thanks.
Andrei.

Later edit: Sorry, I forgot to mention the light: that's 90W T8, Osram fluora, at a actual water column of about 30cm (12 inches)

 

[shoggoth43]

Are all of the plants swaying in the current? Maybe if you move a power head to a different location for different flow patterns? How are you getting the CO2 in there? Maybe switch over to a misting method instead of a reactor? That should be simple enough to try just by feeding the CO2 into one of the powerheads.

Were they all growing well before? I'm finding one of the big gotchas is that things change over time, so what was "enough" at one time doesn't work anymore. Flow, CO2, etc.

-
S

 

[Saniago]

I have been wondering the same thing. Can too much co2 drive plants to grow too fast and become stressed?

 

[incubus3x3x3]

Thanks for answering me.
Yes, all the plants are swaying. The current is pretty strong for a tank at this size. I dissolve the CO2 via an external reactor. I never thought about another method. Maybe that is an ideea.

On the other hand the things were not always went wrong. At some point all plants were growing well, fast and healthy. See photo below, and the movie on the youtube where the growing speed can be seen very well.

The movie: YouTube - Cum cresc plantele...

The photo:

I know the parameters must be adapted while the plant mass grows. But now, I have a smaller plant mass, increased water current, increased CO2... and still nothing.

Maybe I should rely better on the "bubbles per second" than the pH-controller???

Thanks.
Andrei.

 

[VaughnH]

This is exactly where a drop checker is extremely useful. With all of the inaccuracies of drop checkers, at least they can get you into the right ballpark for having enough CO2. Nothing else that doesn't depend on you judging from the appearance of the fish and plants can do that.

The problem with watching the fish, or shrimp for too much CO2 is that without a lot of experience it is very hard to tell when they are showing distress from the CO2. The drop checker ends that confusion, and when it is green you know you have somewhere between 20 and 45 ppm of CO2 in the water.

You can't hurt the plants with CO2, without extreme measures to get more into the water.

 

[shoggoth43]

You might try a simple timer instead of the pH controller. This should get you a more steady rate of CO2 in the tank vs. the controller. The drop checker should give you a better idea of how much is in there and you can go from there.

-
S

 

[incubus3x3x3]

Funny, I just throw my old drop checker to garbage about 2 months ago . Ok, I'll buy a new one. I am really curious about the drop checker readings compared to the controller.

I'll get back to you with the comparison, as i'm sure i'm not the only one asking himself about this.

Thank you all for answering.

 

[incubus3x3x3]

Ok. I followed your advices and bought a JBL drop checker.

I prepared a kh 4 solution from RO water and baking soda (NaHCO3, sodium bicarbonate). I don't know if this was a good ideea since NaHCO3 is not a very stable compound. Whatever. In this conditions, i introduced the drop checker in the tank and waited......

After 2 hours, the solution in the drop checker turned transparent. No color, just transparent. And the drop checker is nowhere near the water flow returning from the CO2 reactor.

Does this mean that I have way too much CO2 in the water? Or it means that my kh4 solution with baking soda is no good? Should I rely better on the carbonates in the tap water, and prepare a kh4 solution from RO water+ tap water?

(I now have Gh=5, kh=3, and pH=5.8 in the tank. I lowered the kh a little,using more RO water at the water change, because I now have some Tonina fluviatilis and Eriocaulon setaceum)

 

[Saniago]

I think you need another drop of bromothymol blue

 

[shoggoth43]

Transparent? Can you put a bit of white plastic behind it? Maybe it's just really faint and another drop or two of your pH indicator would suffice. Another possibility is the pH solution is a bit old and needs replacing, but if it's brand new then it's probably ok.

-
S

 

[Tom Barr]

You might consider cleaning the filter well, adding activated carbon, checking to make sure there's no organic matter, clean and keep it clean.

Often, when things change like this, plants melt/turn white, these particularly........the tap water might have changed, they often add things for the KH during spring and the wet season when all the snow melt runs into the water supply/sources.

So the KH changes a lot seasonally.

This can indirectly affect CO2, and some species.
It really will mess with the pH/KH relationship, I've seen this same CO2 pH/KH level in the Midwest here in the USA.

Like where you live, the seasons are similar and the ground water is embedded in limestone.

So they likely do the same thigns to the tap water.

This is more a additive and KH issue, CO2 indirectly.............but you can help things by doing the water changes and trying to adjust CO2, run activated carbon.

The other alternative is to go full RO water and do a make up with a KH of say 1-2 degrees and a GH of about 3-5.

More work and added cost.
The folks I know with the similar tap have good results, but they cannot trust the pH/Kh at all.

Mostly done by eye and very carefully.
Riccia makes a good indicator for CO2.
Pearls well when happy, about 1/2 way through the day cycle or sooner.


Regards,
Tom Barr

 

[incubus3x3x3]

The problem with the drop checker is now solved by adding 2 more drops of reagent. The colour is now yellow.

The problem with the plants not pearling - solved, don't know how I did notihng than usual dosing and maintainance.
The problem with the Pogostemons (stellatus and helferi) melting - don't know yet. Some of them seem to recover pretty well, some don't. I'll wait and see.

You might consider cleaning the filter well, adding activated carbon, checking to make sure there's no organic matter, clean and keep it clean [...]

Tom, thanks for your advices but, despite that I'm relatively new in using EI (about one year) I have learned the theory pretty well, thanks to you and the other guys around here. I'm even a "preacher" of your method on a forum in my country. So I know the basics (lighting, dosing, CO2, maintainance etc.) well enough to tell to others about them. Practically... well, this is a quite different thing. But, I'm striving.

Seriously now, I did know about some chemicals they put in the tap water somethimes, but I don't think they do that here. The tap water is always around GH=18-20 and kh = 12-14 because my entire region is indeed on limestone soil. (I wonder how did you knew that...?) To make the water acceptable for Toninas and Eriocaulons I have to make a mix of water tap : RO = 1 : 4 so not much of whatever would be in the tap water remains in my tank water... Hopefully.


Thanks again for everything.
All the best.
Andrei.