When to use . Ammonia remover is a specially selected premium grade zeolite based product with a massive surface area to allow rapid adsorption of ammonia which is highly toxic to fish.. This product is used ideally after a filter clean or after adding a number of new fish to the existing population. A suitably sized filter media bag is included for ease of use.. How to use . Rinse well in tap water, place in filter media bag provided, and add to a filter compartment.. Replace after 2-3 months or as necessary.. Use in conjunction with filter media bags.