I have used crushed coral and also sand. Should your about to use sand get a great deal of snails to keep it clean, you do not need for being vacuuming it or stirring it up,it make a mess!! To be able to keep the tank cleanse and nutritious on https://beckettjqpmk.madmouseblog.com/17983364/how-much-you-need-to-expect-you-ll-pay-for-a-good-aquarium-setup-tips