Just noticed my largest of 3 clown fish has lost all his lower fins? Tail is still intact. He is swimming well but ...The 2 smaller ones still have all there fins. There in with a lg Texas Cichlid & a pleco also in tyhe tank. They haver been in the 100 gal tank for at least a year. The tank has a gravel bottom, & someone has been moving it around to clear the bottom...So lots of glass bottom showing? Bacteria on the bottom eating away? I placed him in a 30 gal tank now with goldfish. Hope he will survive...Can I do more for him? Thanks gerry....