Using this Fluval AC Series Bio - Foam is easy. Just insert it into your aquarium power filter. It's designed to fit perfectly, so you don't have to worry about gaps. For both freshwater and saltwater aquariums, this filter insert will work wonders. When it comes to maintenance, remember to replace the bio - foam every 2 months. This ensures that it keeps doing its job of removing waste and promoting beneficial bacteria growth. Always handle it gently when installing or replacing to avoid damaging the foam. With proper use and replacement, your aquarium will have clean and healthy water.