a few minutes ago i wnet up to my room and i saw one of my koi is swimming upsidedown i took an net an transfered the fish to a bucket then i turned on the aerator . note it is floating not at the bottom
What were your water parameters at that time?
Was it newly bought?
What did you feed it?
Tank size?
Temperature?
Filtration?
How many fish do you have in there and how big are they?