BEST VALUE! Set up a routine maintenance schedule with us and we’ll provide everything needed for service. Flat-rate servicing is conducted every two weeks and includes Rowaphos and ROX 0.8 carbon swapped out as dictated by chemical and visual analysis, a 25% water change using freshly prepared RODI water, 14 days worth of top off water, glass/skimmer cup/ filter sock or filter floss cleaning, and water quality analysis of Nitrate, Phosphate, Calcium, Magnesium, and Alkalinity as needed.