My fish tank is 1.5 gallons. I have a betta fish and one of those fish that eat alge. My betta has a minor case of itch and I have been treating it. I have put frops in the water and it hasnt helped much. I know I need to raise the temperature and I found a small heater. It was the smallest I could find but it was for 2-5 gallons. Is it ok if I use that in my tank? Thanks for helping!