Our Coarse Pond Filter Pad is designed to be used in ponds. We have not tested it in marine aquariums. We recommend our Premium True Dual Density Filter Roll for freshwater and marine aquariums. This pad will remove large to fine particles from the aquarium water. Here is an Amazon link to our Premium pads: https://www.amazon.com/Premium-True-Dual-Density-Filter/dp/B01AHIOM8A