Details: This Black Sand Substrate is perfect to make any plant or fish pop against a dark background. Medium sand is the optimal size for plant roots to grow quickly with a firm rooting. The sand is composed of silica with no added dyes, colors or treatments. There may be some harmless residue remaining on the sand, I recommend rinsing several times before adding it to your aquarium. Shipped USPS Priority Mail, Estimated Delivery within 3-5 days after purchase. 1lb per gallon of tank volume will cover the bottom will ~1" of sand Planning for a deeper substrate? Simply multiply the weight needed for your tank by the depth (in inches) of substrate you'd like.