Corys all on their sides and one dead...help
OK so I did my 50% water change last night, and did a major pruning and a 1:20 bleach dip and rescape as I had a slight bout of hair algae. After thorough rinsing of everything, and a Prime and water soak, I replanted, did a thorough gravel vacuum, and a filter cleaning. This morning, all of the corys were sluggish, and some were on their sides. The livebearers, neons and rainbows were perky as usual, and the plecos and otos all busy doing the norm. I did another immediate water change, in case something happened....that is my first quick response to situations like this. Well, a Schwarzi and a Panda are dead and 3 greens are on their sides, one with a red spot on his side. Again all of the rest of the fish are all fine doing the norm. Even the shrimp are all eating and active. All I can deduce so far is that the critters that hang out on the bottom are ill, but the shoalers and top swimmers are all fine.l What do you think could be the issue? I cleaned the eco, and pulled up a lot of plants. Could maybe when I pulled things up I pulled up the iron bottom spikes and they are poisonous? I looked all over and didn't see any of the old flourish root tabs or ADA iron bottom or anything. I have to think either something bad was stirred up or one of the corys was sick and got the rest sick? Does anyone have any ideas? I am crushed.