Sunday one of my fish died, with a bite on it it looked like. I didn't think much, but today my baby angelfish died so I tested everything. I have high ammonia!!!! I got some fizzy things to get rid of it. I am putting any shocked looking fish in a 10 gallon away from the main tank, and to keep ammonia down I'm moving the koi fish my brother put in there. They put about 10 new fish in there, and changed my filter pad 2 days ago, do you think this is what caused the ammonia to spike? Did they make the tank recycle? It's a 46 gallon bowfront that has ran since June. Up until now there were very few fish in it. What else can I do? I am beside myself at the loss if my little angelfish. I just can't let my big one die now.