sketchaire

Thank you. My immediate thought was an ammonia spike and I was shocked when all the parameters came back fine. It must have had something to do with the new sand and maybe the filter. I wonder if anyone else has had a problem with toxins in sand.

I don't know what I did, but here goes: For about 6 months I have had two female betta and four albino corys in a 10 gallon tank with no issues. A month ago I switched from a sponge filter to a hang-on-back AquaClear; I have very hard water (180 GH) and I wanted to be able to add a water pillow to soften it. Then two weeks later I changed the substrate from gravel to sand (prepackaged aquarium sand from PetCo). Everyone looked healthy happy and strong, eating and swimming well. Then on 12/24 I woke up to find all four corys dead with no sign of injury (the two betta are perfectly fine). What did I do to kill them? Was it softening the water too quickly (went from 180 GH to 40 GH in a week)? Ammonia: 0 Nitrates & Nitrite: 0 pH: 6.0 Temp: 78 Thanks for your help. I loved my little corys and I want to be able to keep more but I'm afraid of killing them again.

I own a 5.5 gallon with one male betta, a 10 gallon with two female bettas (and four corys up until last Friday, I'll get to that later), and a small pond with three large goldfish. 🙂