---
product_id: 1627531
title: "Red Sea NO3:PO4-X 500ml NOPOX - Nitrate & Phosphate Reducer for Reef Aquariums, Promotes Healthy Coral Growth, Controls Algae & Maintains Water"
brand: "red sea"
price: "$71.76"
currency: USD
in_stock: true
reviews_count: 13
url: https://www.desertcart.us/products/1627531-red-sea-no3-po4-x-500ml-nopox-nitrate-and-phosphate
store_origin: US
region: United States of America
---

# Compact 3.15x7.87x3.15 in 500ml precision dosing Made in USA quality Red Sea NO3:PO4-X 500ml NOPOX - Nitrate & Phosphate Reducer for Reef Aquariums, Promotes Healthy Coral Growth, Controls Algae & Maintains Water

**Brand:** red sea
**Price:** $71.76
**Availability:** ✅ In Stock

## Summary

> 🌊 Elevate your reef game — clarity and coral health in every drop!

## Quick Answers

- **What is this?** Red Sea NO3:PO4-X 500ml NOPOX - Nitrate & Phosphate Reducer for Reef Aquariums, Promotes Healthy Coral Growth, Controls Algae & Maintains Water by red sea
- **How much does it cost?** $71.76 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/1627531-red-sea-no3-po4-x-500ml-nopox-nitrate-and-phosphate)

## Best For

- red sea enthusiasts

## Why This Product

- Trusted red sea brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Trusted & Tested by Pros:** Top-rated with 4.6 stars and a loyal millennial reef-keeper following.
- • **Clearer Water, Less Algae:** Clinically proven to enhance water clarity and control nuisance algae growth.
- • **Boosts Vibrant Coral Growth:** Promotes healthier coral polyp extension for that enviable reef glow.
- • **Easy Carbon Dosing Simplified:** Proprietary carbon blend makes complex dosing foolproof for busy reef managers.
- • **Precision Nitrate & Phosphate Control:** Scientifically formulated to reduce harmful nitrates & phosphates, keeping your reef pristine.

## Overview

Red Sea NO3:PO4-X is a 500ml US-made biological nitrate and phosphate reducer designed for reef aquariums. It uses a proprietary carbon dosing formula to lower nitrate and phosphate levels, promoting clearer water, healthier coral growth, and effective algae control. Ideal for professional reef keepers seeking a reliable, easy-to-use supplement to maintain optimal aquarium conditions.

## Description

Red Sea Fish Pharm ARE22203 NO3: PO4-X Biological Nitrate and Phosphate Reducer for Aquarium, 500ml

Review: Seems to be effective, but READ the instructions completely - I recently suffered a massive system crash due to high phosphates leaching into my topoff water from the reservoir. I decided to add Red Sea NO3:PO4-X Nitrate & Phosphate Reducer to my repair plan and just see how it went. Now, bear in mind that this was just ONE PART of a multi-step battle plan, so I can't say for sure what worked better, or if anything was useless, or if this was all just blind luck by a dumb guy with a tank, but who knows. I do think it helped, so here's my review: Naturally, desertcart shipping was quick. I read the rest of the reviews, some good, some bad, and decided to give it a go. First off, be sure to read the entire instruction packet. It might seem silly, but there are different dosing regimens for different things you want to do to your tank, so read 'em. When I opened the bottle, I was assaulted by the heady aroma of vinegar and....SOMETHING. Something alcoholic, I think. Yep, you guessed correctly....this stuff is basically a "proprietary blend" of carbon sources. In other words, this is carbon-dosing for idjits. I have no problem with this. I have been afraid of carbon dosing because it seems too fiddly. This product dumbs it down for the rest of us and makes it a relatively easy task. The only thing you need to know about carbon dosing, though, is that once you start, you need to make sure it's done daily. If you decide to stop you need to wean the tank off of it. It's going to promote extra bacterial growth, which will in turn metabolize phosphates and nitrates and bring those terrifying numbers back into an acceptable range. The product claims that this will also promote clarity of the water and greater polyp extension. Well, it's been a few weeks since I started, and I can definitely see a lot of improvement. Dunno if it's the GFO, the UV filter, the massive water change, the Red Sea Reducer, or (most likely) a combination off all of the above. But I DO see much clearer water and coral polyp extension has been great, so I'm gonna go ahead and call that a win for this particular product. My phosphates have dropped from 0.18 on a Hanna checker down to 0.02, and my tank is back to happy again. I'd recommend this product, but I want people to be aware that this IS a carbon dosing source, and those instructions have to be fully read and understood before you start.
Review: It really works! - It took a while to arrive and based on what I read online I started slowly using about 1/2 the recommended dosage. It worked a little, so I increased the dosage to recommended levels. Wow! It works great and has reduced the nitrate level in my fish only tank considerably and my algae problem is under control. Note, I dosed by hand daily as I do not have a dosing pump.

## Features

- Country Of Origin: United States
- The Package Length Of The Product Is 3 Inches
- The Package Width Of The Product Is 3 Inches
- The Package Height Of The Product Is 8 Inches

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B006L48D3U |
| Allergen Information | Cashews Free |
| Best Sellers Rank | #44,214 in Pet Supplies ( See Top 100 in Pet Supplies ) #423 in Aquarium Water Treatments |
| Brand | Red Sea |
| Brand Name | Red Sea |
| Customer Reviews | 4.6 out of 5 stars 575 Reviews |
| Global Trade Identification Number | 00730773222032 |
| Included Components | PHL306049 |
| Item Form | Liquid |
| Item Type Name | aquarium supplement |
| Item Weight | 1 Pounds |
| Liquid Volume | 500 Milliliters |
| Manufacturer | TopDawg Pet Supply |
| Manufacturer Part Number | 306049 |
| Model Number | 306049 |
| Pet Type | Fish |
| Target Species | Fish |
| UPC | 730773222032 |
| Unit Count | 500 Milliliters |

## Product Details

- **Brand:** Red Sea
- **Item Form:** Liquid
- **Item Weight:** 1 Pounds
- **Liquid Volume:** 500 Milliliters
- **Manufacturer:** TopDawg Pet Supply

## Images

![Red Sea NO3:PO4-X 500ml NOPOX - Nitrate & Phosphate Reducer for Reef Aquariums, Promotes Healthy Coral Growth, Controls Algae & Maintains Water - Image 1](https://m.media-amazon.com/images/I/616rw6PL5yL.jpg)
![Red Sea NO3:PO4-X 500ml NOPOX - Nitrate & Phosphate Reducer for Reef Aquariums, Promotes Healthy Coral Growth, Controls Algae & Maintains Water - Image 2](https://m.media-amazon.com/images/I/81SY16fGxyL.jpg)
![Red Sea NO3:PO4-X 500ml NOPOX - Nitrate & Phosphate Reducer for Reef Aquariums, Promotes Healthy Coral Growth, Controls Algae & Maintains Water - Image 3](https://m.media-amazon.com/images/I/71N3PqCA8mL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Seems to be effective, but READ the instructions completely
*by R***D on February 23, 2014*

I recently suffered a massive system crash due to high phosphates leaching into my topoff water from the reservoir. I decided to add Red Sea NO3:PO4-X Nitrate & Phosphate Reducer to my repair plan and just see how it went. Now, bear in mind that this was just ONE PART of a multi-step battle plan, so I can't say for sure what worked better, or if anything was useless, or if this was all just blind luck by a dumb guy with a tank, but who knows. I do think it helped, so here's my review: Naturally, Amazon shipping was quick. I read the rest of the reviews, some good, some bad, and decided to give it a go. First off, be sure to read the entire instruction packet. It might seem silly, but there are different dosing regimens for different things you want to do to your tank, so read 'em. When I opened the bottle, I was assaulted by the heady aroma of vinegar and....SOMETHING. Something alcoholic, I think. Yep, you guessed correctly....this stuff is basically a "proprietary blend" of carbon sources. In other words, this is carbon-dosing for idjits. I have no problem with this. I have been afraid of carbon dosing because it seems too fiddly. This product dumbs it down for the rest of us and makes it a relatively easy task. The only thing you need to know about carbon dosing, though, is that once you start, you need to make sure it's done daily. If you decide to stop you need to wean the tank off of it. It's going to promote extra bacterial growth, which will in turn metabolize phosphates and nitrates and bring those terrifying numbers back into an acceptable range. The product claims that this will also promote clarity of the water and greater polyp extension. Well, it's been a few weeks since I started, and I can definitely see a lot of improvement. Dunno if it's the GFO, the UV filter, the massive water change, the Red Sea Reducer, or (most likely) a combination off all of the above. But I DO see much clearer water and coral polyp extension has been great, so I'm gonna go ahead and call that a win for this particular product. My phosphates have dropped from 0.18 on a Hanna checker down to 0.02, and my tank is back to happy again. I'd recommend this product, but I want people to be aware that this IS a carbon dosing source, and those instructions have to be fully read and understood before you start.

### ⭐⭐⭐⭐⭐ It really works!
*by M***. on February 12, 2025*

It took a while to arrive and based on what I read online I started slowly using about 1/2 the recommended dosage. It worked a little, so I increased the dosage to recommended levels. Wow! It works great and has reduced the nitrate level in my fish only tank considerably and my algae problem is under control. Note, I dosed by hand daily as I do not have a dosing pump.

### ⭐⭐⭐⭐⭐ It really works!!
*by J***N on August 20, 2016*

Heard nothing but good stuff about this. I had problems with high nitrates in my predator fowlr tank. I didn't want to do macro of biopellets. Besides I heard this stuff work much better and faster. I got 100 g DT and 55 sump. I called red sea and they gave me the info I needed for how much to dose my tank, depending on your nutrients levels. I'm dosing the max dose 3ml per 25 gallons. Its been a week since I've started dosing and my nitrates were at 80ppm before dosing. Now there at 20a week after dosing. I have a yellow head moray eel and Him alone is a big bio load. I'm already satisfied with results and it haven't been a month of using this product. I don't need undetectable nitrates But under 20 I can live with. I'll be using this as long as im in the marine hobby.

## Frequently Bought Together

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-05-15*