His name is Nacho and he has had this problem of having one piece of his mouth loose and he would be mellow for a few days, then it would disappear and he was fine and happy. Then we had a garage fire and we stayed at my aunts house, they (my fish Taco and Nacho) went from living in a filtered 10 gallon tank to a one gallon jar for a week and a half, they did fine and survived. We then got a rental house, and I got their tank back and put them in there. I put about 95% new water in there, and the water is from the same source as before. They have now lived in there again for about 3 weeks, and it seems like these last 2 weeks, Nacho has had a piece of skin on either side of his mouth loose. I thought it would go away as it did before, but now it is getting worse. His face seems to be peeling back from the top of his mouth upwards. I think it hurts him a bit because he barely eats. I looked up what could be happening, and I got this, http://answers.yahoo.com/question/index?qid=20080914102158AALHldQ So, they say that it may be a bacterial or fungal thing, so we were wondering if we could put Grape Fruit Seed Extract in there, as it is good at getting rid of bacteria. Anyway, we will go ahead with putting the GFSE in there, but if anyone knows for sure that you can't do that, or what it is called that Nacho has, then please reply. Thanks.