He has a tiny bump on the bottom ( it doesn't cover the whole bottom). it is on one side of the bichir, and so it's pretty small. On july 10th, My dad and I will clean the 30 gallon tank, and buy metronidazoile. Will he be fine? he has had the bump about a month. he's acting normal, he also is not skinny, and he eats alot. (this threat was started july 9)