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Red Sea NO3 PO4 - X Algae Management Supplement, Phosphate and Nitrate Reducer

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Highly effective, controlled, biological reduction of nitrates and phosphates for all reef and marine fish systems. Promotes coral growth and coloration

NO3 - PO4 


  • 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.

Implementation Guide

Aquarium Type Recommended
level of
Test kit
Average daily usage
of  NO3:PO4-X (25gal)
  NO3 PO4    
Mixed Reef 1-2ppm 0.08-0.12ppm NITRATE | NITRITE
SPS Frag 1-2ppm 0.08-0.12ppm NITRATE | NITRITE
SPS Dominant 0.25-0.5ppm 0.01-0.02ppm ALGAE CONTROL PRO 1-2ml
Ultra Low
nutrient SPS
0ppm 0ppm ALGAE CONTROL PRO  1-2ml 
Marine Fish <10 <1 NITRATE | NITRITE 3ml





   Algae Management Program      BFA #
   NO3:PO4 - X         RS22003




Comparing NO3: PO4-X to other methods of algae nutrient reduction:

Red Sea’s NO3: PO4-X algae management program provides a complete solution because it is controllable and deals with both nitrate and phosphate, in comparison to other methods that are lacking in some part of the process. The following table reviews most of the current methods of dealing with nitrate and or phosphate:

NO3: PO4-X is easy to use, with a relatively small dose being added to the system on a daily basis. Over time the daily dosage of NO3: PO4-X will be varied (see instructions for use) according to measured levels of nitrate and phosphate, giving the fine control of nitrate and phosphate levels that guarantees the gradual changes and accurate maintenance of the desired nutrient levels.


New tanks, untreated established tanks and established tanks that have used alternative methods of nitrate and/or phosphate reduction will all react differently when starting to use NO3: PO4– X. However over time the nutrient levels will stabilize as desired, irrespective of where they started. (For specific instructions for converting to NO3: PO4-X from PO4 absorbers and/or NO3 de-nitrators click here)


With continued correct use there are no undesirable side effects when using NO3: PO4-X. It is safe for all fish, corals and micro fauna. Even a large accidental overdose should not cause any irreversible damage as long as a suitably rated skimmer is installed on the system


Red Sea NO3: PO4-X is available in 500ml and 1000ml bottles and includes a measuring cup for easy dosing.


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.