Red Sea No3Po4-X - Biological Nitrate & Phosphate Reducer Highly effective reef-safe solution for the long term prevention of algae through precise control of nitrates & phosphates.Controllable and safe nitrate & phosphate reduction.Sets and maintains ongoing desired levels of nitrate and phosphate.Promotes coral growth and coloration.Reef Safe no undesirable side effects.Easy to use reliable and cost effective.Red Sea NO3: PO4-X is a unique complex of a number of different carbon molecules and other organic-bonded elements that enable a controlled biological reduction of algae nutrients (nitrate and phosphate) by naturally occurring nutrient reducing bacteria that exist in all aquariums.