^that was my first thought too. Seeing as how the cory and the tetras need bigger groups to begin with.
I'd say test water asap. If you have qt tanks I'd suggest splitting the fish up and qt'ing them.
Have you introduced anything new to the tank? (ie, fish, plants, decor, etc)
That sucks though!
"Fish are friends, not food."
Elway the Bronco Betta - Halfmoon
Baby Chi - HM
4 Twin Goldbar Platy, 12 Cardinal Neons & BN Pleco - Unnamed. "
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