I need as much help as possible. I have just started taking care of my fathers angelfish over break. I was wondering like what Ph they need. What temp. Any special thing they should have in their tank? He has had the tank for a while and it hasnt been cleaned in a while. Im usre I did about a 40% water change when I cleaned the gravel to day and that was only like half the tank. He has 3 angels in a 30 gallon. They range from 2-3 inches in diameter in body size(not including fins). I dont know if one of them is sick or not b/c right around its gills its kinda red and it looks almost like its busting out. Like around its gills the body puffs out from them. Is this normal??