I just had the exact same problem. I lost one glass catfish, one neon so far, and I have one zebra barb wiggling upside down and sideways. The other three neons look a little stiff and strange, but the other fish seem alright. Bettas and pleco don't show any symptoms.
I suspect that in both our cases it was a chlorine spike. For me, I did an 85% water change and forgot to add Prime before putting the fish in. I realized this maybe 10 seconds later, but by then it had already affected the fish. I scooped everyone out into various fishbowls, but I wasn't quite quick enough for a few.
All my numbers look good, so it isn't the ph or ammonia or anything. Since I forgot the dechlorinator, I suspect we both suffered from chlorine poisoning.
It's terrible to lose fish this way. I hate to see them suffer so.
I suspect that in both our cases it was a chlorine spike. For me, I did an 85% water change and forgot to add Prime before putting the fish in. I realized this maybe 10 seconds later, but by then it had already affected the fish. I scooped everyone out into various fishbowls, but I wasn't quite quick enough for a few.
All my numbers look good, so it isn't the ph or ammonia or anything. Since I forgot the dechlorinator, I suspect we both suffered from chlorine poisoning.
It's terrible to lose fish this way. I hate to see them suffer so.