Lana, I transferred this from "sick axie: red rash message" that I answered.
Lana, you've now obviously worked out axies don't need heaters. They prefer cooler temps (from 5 deg cel. to 20 deg cel.) when it starts rising above 22-24 deg cel. you will have to start cooling it down. Get a thermometer, if you don't have one.
(Message edited by kapo on September 25, 2006)
Also, sounds like your tank may be cycling, esp. since you changed him to new one recently. You will need to test the water regularly for ammonia, nitrite and nitrate regularly (every few days) while cycling. See:
http://www.caudata.org/cc/articles/cyclingEDK.shtml If you don't have test kits to test the tankwater then take a sample, asap to your petshop and get them to test and give you the figures of the reading. If the ammonia and/or nitrite readings are too high, which can cause skin to peel/shrivel or "burn", you will need to do a 20-30% waterchange to bring water back into safer levels for your axie. If ur unsure what your readings mean, post a new thread here and ask.
Try and keep the tank cool below 18-20deg cel. and if ur unable to get your water tested within the next day or so, then do a 20-30% waterchange to be on safe side.
Also, can you post a picture so we can see if it is fungus? If it is fungal, then saltbaths will need to be done 2-3 times daily.