piranhaking
New member
Im working on a 75 gallon saltwater aquarium for my school. THe tank currently has about 2 or 3 inches of crushed coral substrate( i know its a terrible choice, but it was there when i started working on the tank.) Since were on a limited budget they wont let me completely redo the whole sand bed with sugar fine sand, but they did ok me to buy 60 lbs (dry weight). My question is would i be better off to just add the sugar sand to the top of what is there, or to remove some of the crushed coral that is currently in there?