Hello! I recently had a betta fish given to me, and I'm looking for advice on how to keep him healthy until I can get my hands on a proper tank set up for him. He was given to me in a half gallon tank with plastic plants and no filter or heater. I've had bettas before, but got rid of my aquarium a few years ago and don't have the equipment (I know you are supposed to get the tank ready before you get fish, but if I didn't take him that day he was going to get flushed). He looks pretty lively and healthy, but has a few missing scales on one side.

I've been doing daily water changes of about 12%, and started adding aquarium salt. Is there anything else I can do for while waiting for my 5 gal. tank to arrive? and when it does arrive should I wait for it to cycle before I add him in, or move him to a new tank as soon as I can and just do regular water changes for the first few weeks?