Ok redoing my 72 gallon bowfront and I need to know how much flourite Im going to need to cover the bottom of the tank. Im going with Florite black sand. Tank is 48" long and at the widest point its 19" wide. Im going to be combining 2 planted tanks into this one. I have seven tanks going now and I when Im done I should only have 4 tanks up and running. Right now my fish are spred out all over the place and its to much work right now plus my power bill went from $50 bucks a month to $150 a month.