Another question about treating ick?

Nope. You need to do a 25% water change first then treat the water. Wait until the ich is completely gone then do a bigger water change and clean the gravel also and yes you'll probably need to treat your other tank as well because ich is transferable. If your net was in the tank with ich you will need to soak it in boiling water maybe even in a little bit of medicine to help disinfect it.