If you recall a few days ago I posted a picture of Kyorbit looking like this:
Well I just added him to his ten gallon tank, two days later I did a 50% water change, and OVERNIGHT he changed into this:
Mind you, this is OVERNIGHT! About 7 hours!! I added the correct amount of water conditioner, I didn't do anything funky, and I JUST did a water change so how can it be fin rot? I'm so terrified and I have no idea how to treat this. He tries to eat his pellets but spits them back out...he'll eat freeze-dried bloodworms. He doesn't move around much and is getting worse by the hour.