[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Newbie

Thomas Barr wrote:
> You want to use CO2 to acidify your water and drop your ph to about 6.8-7.0.

Be careful!  Assuming that Tierney is measuring a pH of 7.8 with a 
fish-produced CO2 concentration of about 3 ppm, bringing it all the
way down to pH 6.8 could be a lethal dose of CO2 for the fish.

My tank pH without CO2 injection usually measures about 7.8.  If I
vigorously aerate the water for a while (in a jar, no fish) it
comes up to about pH 8.0.  According to a semi-reliable source,
this equilibrium with atmospheric CO2 should produce a CO2
concentration of 0.68 ppm.  That means my normal CO2 (non-injected)
is about 1 ppm, which is believable (if a little low) with fish
and plants.  I'm now dropping it down to aroud 7.0 with CO2
injection, and I notice mild respiratory distress ("panting") in
the fish beginning at about pH 6.8.

David Ozenne
Fremont, CA