I'm dosing standard KH2PO4 plus feeding the few current inhabitants, so I'm at a loss to explain it.
The marking on the needle valve was put there long before the nitrate problem was discovered. Is it possible the shrimp and fish were unusually susceptible to CO2 because of the nitrate stress?
If so, maybe the issue really is CO2 once the nitrate problem is gone.
Last edited by Rainer; 10-11-2012 at 04:40 PM.