I have a male betta (his name is Alpha Neptune... "Alphie" for short :3) that's been living in a 1.5 gal., filtered but unheated tank since about October (I believe). I typically keep my room heated above room temperature (it's at about 23-24 degrees celsius right now) to compensate... I just can't find a heater small enough that I trust not to boil my fish. My mom won't let me get a bigger tank. :(
Anyways, about three weeks ago I went on vacation and transferred Alphie's tank to my Grandmother's house for a week. When I got back the poor thing was hiding behind his filter and there was tons of excess flakes sitting at the top. The water hadn't been changed either and there was lots of algae. I probably should have given my grandmother stricter instructions, but at least he lived.. xD
So I got him home, changed his water. It took a few days, but he came out from behind his filter and was swimming around normally again. I think it was around this time that I noticed he had a white-ish patch on top of him, just before the dorsal fin. I couldn't remember if this was normal or not, and he seemed fine, so I just ignored it. (this was two weeks ago)
An hour ago I noticed that the white patch is gone, and it looks like he has two sores in its place. It looks like in humans if you have a blister that's peeling off. Alphie's acting normal but it was rather alarming. I tested for ammonia and it came up as "0".
I've attached pictures... He's a bit camera shy, so it was hard. :P And if the tank looks really green... that's because I haven't cleaned it since Thursday. Usually I clean and do 50% water changes twice a week. The algae builds up super fast. :(
I'll see if I can get more pictures tomorrow... in all three you can clearly see the bigger sore. In the second one, you can see the smaller sore on the side as well.
Is this bad? Should I get any medication or anything for it?