Balloon Bellied Molly suddenly swimming vertically after I did a water change. I cleaned my 5 Gallon aquarium this afternoon and after I added the new water my male balloon bellied molly began having trouble swimming and started tilting backwards and swimming vertically. Sometimes he even spins while trying to straighten himself again. This doesn't happen all the time, but often enough for me to worry. I read somewhere that giving him shelled peas will help him, but does it really?
Any suggestions would be greatly appreciated.

If it matters I am also treating the tank for Ich right now.