Curing rock and cycling it are basically the same thing. You cycle your tank to build up the beneficial bacteria for your nitrate cycle so your fish don't die. If you have a tank already established, you cure your rock in a separate container to prevent die off from the rock from causing a parameter spike and poisoning your fish.
There is filter media like GFO
, Chemipure, and there are others. The best way to remove phosphates is to simply prevent it from going in by using ro
water and feeding sparingly or rinsing off frozen food.