Choose the substrate you wish to use below, then fill in the tank floor dimensions and the depth of substrate you require and click on 'Submit' to get your substrate amount estimate at the bottom. Substrate type you wish to use:  Coral Sand Eco-Complete Fine Sand Flourite Live Sand Regular Gravel Length of tank:  Inches    Width of tank:  Inches Substrate depth required:  Inches                  lbs needed to achive the substrate depth required.