top of page
Red Sea NO3:PO4-X  1 Litre

Red Sea NO3:PO4-X 1 Litre

SKU: T948

Red Sea NO3:PO4-X, available in a convenient 1 Litre bottle, is your ultimate solution for algae management and nutrient control in reef and marine fish systems. This reef-safe formula provides a controllable method for reducing nitrate and phosphate levels, promoting optimal coral growth and vibrant coloration. Unlike other methods, NO3:PO4-X biologically reduces both nitrate and phosphate while allowing fine control of their levels. This unique complex of carbon substances enhances the activity of nutrient-reducing bacteria, ensuring a complete and safe denitrification process. Easy to use, reliable, and cost-effective, NO3:PO4-X reduces nuisance algae without undesirable side effects. For best results, maintain controlled nutrient levels using an accurate test kit and efficient protein skimming. Elevate your aquarium's health with Red Sea's NO3:PO4-X.

Red Sea NO3:PO4-X  1 Litre


A complete, reef-safe, controllable solution for nitrate & phosphate reduction

NO3:PO4-X is the original, safest, most popular, and best solution that provides a full, reef-safe, controllable method for nitrate and phosphate reduction, thereby boosting coral growth and coloration in any reef or marine fish system.


Unlike other methods, the monitored dosing of NO3:PO4-X biologically reduces both nitrate and phosphate, while enabling the fine control of their levels. This fine control allows gradual changes and guarantees accurate maintenance of algae nutrient levels required to safely reduce nuisance algae and bring the symbiotic zooxanthellae algae to the optimal levels needed for boosting coral growth and coloration.


NO3:PO4-X is a unique complex of carbon substances and other organically bound elements that enhances the activity of nutrient reducing bacteria, which naturally exist in all marine aquariums. Each carbon source in the complex is utilized by different strains of microorganisms and together with the balanced ratio of enzymatic co-factors guarantee a complete and safe denitrification process (nitrate reduction) and phosphate reduction in the aquarium.

To learn more about the scientific aspects click here.


* Efficient protein skimming is critical to the safe use of NO3:PO4-X.


  • Enables controlled nitrate and phosphate reduction for optimal coral growth and coloration
  • Reduces nuisance algae
  • Reef-Safe, with no undesirable side effects
  • Easy to use, reliable and cost-effective

Notes For Use

  • Uncontrolled reduction of the algae nutrients can destroy the symbiotic Zooxanthellae causing UV shock and starvation of the corals. For best results always use an accurate test kit such as Red Sea’s Nitrate Pro test which has an accuracy of 0.125ppm.

  • Once lower levels are nutrients are achieved, as seen by corals displaying their natural colors instead of “Zooxanthellae” brown, it is important to start feeding with easily digestible foods such as Red Sea’s Reef Energy 2-part formula that contains all of the necessary carbohydrates, amino acids, and vitamins.


    Efficient protein skimming is essential to provide the necessary oxygenation of the water and to remove bacterial flocks from the aquarium.

More Information

bottom of page