I'm looking to find a more self-sustainable method to reduce nitrates in my 55 gallon tank. The tank is heavily stocked with cichlids, and I want to find a plant to help reduce the nitrate levels so I don't have to change the water every 3-4 days. I do plan to use a sump tank (a 10 or 15 gallon tank with 100 watt HPS). Reducing my stock is not an option because crowding my tank has kept my fish's temperament in check.