Well seeing as he's in a 1 gallon tank, you're going to have to do 100% water changes a couple of times a week. I had mine in a 1 gallon for about a week and did 2 100%s and 2 50%s. They are hardy, and should tolerate the water changes very well if you handle him with care.
You should get something made just for Ich from the pet store. I'm loyal to Maracide, and know a few people who swear by Coppersafe, but it's all up to you.
Clean his WHOLE tank, decorations, rocks, everything, with very hot water. No CLEANERS! Set up the new water (remember the conditioner!) and let him float in it a while, then, when he's back in, add the medication per the instructions. It should only take a couple of days to work.
As a side note.. You really should look into getting a larger tank for him. Rule of thumb is 1 inch of fish = 1 gallon of water. Bettas do a lot better in a 2.5 gallon tank, or larger, and you won't have to clean it as much! But with the little 1 gallon you have him in now.. you better get over the fear of changing water.
Last edited by MollyJean; 01-17-2010 at 06:51 PM.