Re: CO2

["David A. Youngker" <nestor10@mindspring.com>]

From: Patrick Claytor
Sent: Thursday, August 03, 2000 5:01 PM

> Does anyone know if CO2 injection has any illeffects on
> Apisto tanks(raises hardness/pH?). The reason I am
> asking is becouse the only Apisto losses I have had were
> in a CO2 injected tank. The Apistos were A. borellii. The
> parimiters at death were pH: 6.5 KH: 11dKH(rose ~7dKH)
> GH: 5dGH ammonia and nitrite were undetectable...

One _possible_ problem would be the amount of CO2 present in the water of
this tank.

Even at the lower concentration of 4 dKH (11-7), it would take over 30 ppm
CO2 to achieve a pH of 6.5. The situation is far worse at the levels
required to do the same at 11 dKH.

Some fish don't handle this very well. A good description of what's going on
in cases of CO2 poisoning can be found at
http://www.thekrib.com/Plants/CO2/poison.html . Have you noticed any of the
symptoms discussed there?

> The water was about 75% DI and 25% tap and peat
> filtered...

This would imply a starting value of around 12 dKH then. Hmm - and exposure
to your tank raises it back to almost the same level, so I would guess that
there's a carbonate source somewhere in the tank also. But I can assure you
that it's not the CO2 that's responsible.

Taken with the following statement,

> moderatly planted with many caves...

makes me want to ask what you're using as substrate. Or are there any rocks
used as caves, terracing support, etc.? Have you tested them for carbonate
content?

Are you using the same thing(s) in all of the other, non-problematic tanks?
Are their GH and KH on an equal footing? If not, what *else* is different
with this tank other than the enrichment?

> My A. sp. "Rio molome" have been doing fine.

That may only mean that they're more tolerant, or more native to, such
acidity and CO2 concentrations. Quite a few black waters can reach the sub-5
pH range at times...

-Y-

David A. Youngker
nestor10@mindspring.com





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