When it comes to phosphate control in our aquariums, most hobbyists use water changes and GFO to remove it, but many still don’t know how to effectively limit its introduction. Phosphate can enter into the aquarium any number of different ways. It is present in live rock and different substrates, many different additives, and even fish food. So, a big part of phosphate removal is in prevention itself. To accomplish this, it’s best to use quality water, first and foremost. It is also very important to rinse filter media in RO/DI water, soak live rock and sand prior to introducing it into the aquarium, was frozen fish foods to remove their binding materials, and use trusted aquarium additive products. These steps are effective, but obviously there is no guarantee on completely preventing phosphate from entering into the aquarium via these sources. Because of this, constant use of GFO and regular water changes are pretty much a must have.