Tamara,
Thanks for the link. We have all our tanks on GFI outlets, so if the problem was electrical, the tank would have shut down.
Michael,
I suppose the fish deaths could have resulted from ammonia, though I estimate only .5 ppm could have been in the tank before the water change. The ammonia would have not instantly occurred, I don't think. It would have taken awhile for it to build up, right, especially with all that macroa algae in the tank? And even at .5 ppm, that wouldn't be enough to kill so quickly, would it? After the 40% w/c there was .5 ppm ammonia in the tank. Tested water from the RO/Di unit this morning and it was .5 ppm
