Red Sea

NO3:PO4-X Nitrate & Phosphate Reducer

Grouped product items
500mL NO3:PO4-X Reducer

SKU: 208218

In stock


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1000mL NO3:PO4-X Reducer

SKU: 208219

In stock


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Prevent algae breakouts by removing the nitrates and phosphates in your reef tank. NO3:PO4-X Nitrate & Phosphate Reducer from Red Sea is a complex of carbons each with a different strain of microorganisms in a reef ready solution.

Three Sizes Available

  • 500mL
  • 1000mL


Red Sea's NO3:PO4-x is a part of their Algae Management Program that combines highly effective, controlled biological reduction of nitrates and phosphates for all reef and marine aquariums. Between testing and dosing the proper additives, nutrients in the aquarium can be easily managed with no undesirable effects. NO3:PO4-x helps promote naturally occurring nutrient-reducing bacteria that already exist in your aquarium. 


  • Reduces and maintains NO3 and PO4
  • Cost Effective
  • 100% Reef Safe (do not overdose)
  • Nitrate and Phosphate reduction in a controlled setting


Dosage Guide:

We highly recommend starting with half the recommended dose for your aquarium type and using high-quality Nitrate and Phosphate test kits during implementation. Keeping a steady dosing regime is key, and daily dosing is highly encouraged. We prefer to use a dosing pump system for daily dosing, which keeps the doses very precise and reliable.

Aquarium Type


NO3 Level


PO4 Level

Average Daily

Dose of NO3-PO4-X

Mixed Reef 1-2ppm 0.08 - 0.12ppm 2mL per 25 gallons
SPS Frags 1-2ppm 0.08 - 0.12ppm 2mL per 25 gallons
SPS Dominant 0.25 - 0.5ppm 0.01 - 0.02ppm 1-2mL per 25 gallons
Ultra Low Nutrient SPS 0ppm 0ppm 1-2mL per 25 gallons
Marine Fish <10ppm <1ppm 3mL per 25 gallons
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Product Questions

Hi I was wondering if this product expires or gets old and breaks down? Trying to determine what size bottle to get because I have a smaller tank and it last so long I dont want it to go bad before I can use it up, thanks
Question by: Taylor on Feb 2, 2020, 10:14 AM
Hey there,

As long as you keep it well sealed and away from excessive heat it should last as long as you need.

Take care
Answer by: Thomas Billington on Feb 6, 2020, 12:37 PM
I have a 10 gallon reef tank. How much of this product would I use in my tank or would it be too much for my tank?
Question by: JONATHAN SHIER on Feb 1, 2020, 12:52 PM
Hey there,

You will use 2ml per 25 gallons of water.

Take care
Answer by: Thomas Billington on Feb 6, 2020, 10:01 AM
I really appreciate BRS, all the videos are so helpful. You put in so much work in the BRS 52 weeks and Investigates My tank in a 33 gal cube with all HOB equipment. I have a good skimmer and I only have 7 small fish. I was feeding 2 sun corals and this is when my NO3 went up to as high as 100. and the p04 to .2 I started using Rowaphos and vodka dosing. My p04 in now .03. N03 is still 25-50. Will NOPOX do a faster job of lowering my nitrates? I've been using vodka since 8/11. My currant dose is 3,7ml/day. Thank you
Question by: Lisa DiMercurio on Oct 8, 2017, 9:44 PM
Hey there,
Thanks for getting in touch with us in regards to lowering your nutrients with NOPOX. I am not sure if this would lower it quicker, but I personally would feel it to be more of a stable additive then vodka as its made specifically for aquarium use. I have although seen a few tanks maintained with vodka with amazing results. Please let me know if there is anything else that we can assist with. Thanks!
Answer by: Tyler Schafer on Oct 14, 2017, 3:19 PM
I travel a lot with my job so I can't always dose daily. Can NOPOX be added with a dosing pump?
Question by: Ryan Lowder on Jun 1, 2017, 9:28 PM
There should be no issues with setting this up with an automated doser. We know of quite a few customers doing just this.

Happy reefing!
Answer by: Zack on Jun 8, 2017, 10:58 AM
I recently moved and setup my reef tank. The tank has begun showing diatoms. Is this product recommend during the tank cycling process? Will it help rid my tank of diatoms?
Question by: Eric Thatcher on May 3, 2016, 10:35 AM
Great question!
This product will decrease nitrate levels in the tank by feeding the bacteria and growing the population that additionally consume nitrates. Diatoms will typically not be impacted and usually will fade after a few days without light or siphoning out.
Answer by: Connor on May 3, 2016, 4:59 PM
If my tank is running very low to 0 nitrate and phosphates is this still recomended if I want to build benificial bacteria like the product claims?
Question by: Nick Castillo on Apr 24, 2016, 7:13 PM
Great question!
You will not need to use this product if your levels are undetectable. While this provides food for bacteria it will most likely result in over dosing and issues such as excess bacteria such as Cyano.
Answer by: Connor on Apr 27, 2016, 2:19 PM
Can I use Red Seas No3PO4x added in with my ATO/Kalk? I make up a weeks worth at a time. I'm away from home frequetly so the daily measure and addition of the liquid is not possible.
Question by: Mike Ornellas on Apr 15, 2016, 5:55 PM
Great question!
It may be possible however you would need to perform some math by seeing how much Top Off water you add each day. We do not recommend this as the nopox will settle out in the RO water and not be mixed evenly. Feel free to let us know if you have any further questions!
Answer by: Connor on Apr 20, 2016, 12:22 PM
If all is reading well is this safe to use daily! Just to keep all under control
Question by: delores on Apr 13, 2016, 10:52 AM
Great question!
This is recommended for daily use for keeping up with nitrate levels. Feel free to let us know if you have any further questions!
Answer by: Connor on Apr 13, 2016, 3:17 PM
while using NOPOX can i still run my U/V sterilizer?
Question by: brent matura on Jan 13, 2016, 4:20 AM
Great question!
Typically with Bacteria growth systems such as NoPox, Zeovit, and Bio-pellets it is not recommended to run UV sterilizers as they can keep the bacteria from repopulating in the tank as needed! Feel free to let us know if you have any further questions!
Answer by: Connor on Jan 13, 2016, 1:48 PM