Instructions: If desired, briefly rinse substrate in (preferably) purified water prior to placement in aquarium system to remove dust. KoraLagoon Substrat may be employed in a number of applications, however in each case it is recommended that the total depth of substrate not exceed 2.0 in. (5.1 cm). To determine the approximate amount of KoraLagoon Substrat (lbs.) required for a given container (e.g. aquarium, refugium, or sump), multiply the inside length and width of the container (in.) by the desired depth of substrate (in.), then multiply the result by 0.05. For example, a refugium with internal dimensions of 18 in. by 12 in. and desired substrate depth of 2 in.