what do you use for sick fish?

It depends on what they have. There isn't a cure all for fish diseases.

There are three main types of diseases.

Fungal, Bacterial, and Parasitic.

Two products you should keep on hand are Pimafix and Melafix. They are natural products that are for fungal and bacteria infections, if caught right away.

 

Pima and Melafix are two things I keep under my tank all the time

 

I cannot agree more with anthony and yellow, in addition to pimafix and melafix, I always keep a bottle of ick medicine on hand as well.

 

Personally I don't use meds for ick. I had it once when I purchased two female peacock cichlids that developed it the day after I purchased them. I used the heat and salt method for a day then removed the salt and just used heat to speed up the ick cycle and kill them.

 

If you keep up with regular partial water changes, you should very rarely have a sick fish. Water changes are the single most important thing you can do to insure fish health.

 

I agree with all of you. I keep the three items you mentioned and also keep Maroxy because I have egg layers and it helps to keep the fungus off of them.

 

Fish Medications and Usage Guide

This should be helpful in treatment of sick fish and water conditions that are poor and problematic in your tank.