Questions about Ich after treatment? When can I add carbon back into my filter? Why is my water staying cloudy? Why are my fish less active? Should I change all of my water and how soon after treatment? Any other helpful info would be a BIG help! This is my first tank, and has been up and running for three weeks now, I added 2 bala sharks the next day, one was dead, and now today I lost a Blue Guiama.