This package is ideal for Nano reef aquariums up to 10 gallons. It contains a carefully selected mix of herbivores, detritivores, and omnivores. By utilizing these cleaning organisms, and good overall husbandry practices, aquarists will minimize their algae and detritus cleaning responsibilities. This Cleaner Package has 4 Scarlet Hermit Crabs, 8 Astraea Snails, 5 Cerith Snails, 10 Nassarius Snails. For larger aquariums, up to 30 gallons, just order multiple quantities of this package accordingly.