I have a delta tail betta named Hank. He is in a 5.5 gallon tank with a heater and a sponge filter. He has been eating well since i got him which wasnt that long ago. The problem is that his tail has been ripping. I have changed out the decor several times thinking that that may be what is doing it but there has been no improvement. I thought that it may be fin rot but there is no discoloration in his fins around the tears. The only thing that i can think of would be the ph which tends to run high in my tank. Any suggestions?