Originally Posted by DvanK
Your tank and your living room looks very nice and clean. What happened to the fish once you changed the water? Were they gasping for air? It seems a little strange that co2 in the well would kill your fish.
It was very strange, but the only thing that seemed to make sense (more discussion here http://www.plantedtank.net/forums/sh...d.php?t=189554
Put a cup of tap (well) water on the counter, after 12 hours the Ph had risen substantially.
Some fish were hanging at the top - and the ones that died were hanging motionless, like they were stunned, swimming/moving a bit before becoming still again.