API Nitrate NO3 Freshwater & Saltwater Aquarium Test Kit, 90 count

Rated 4.6667 out of 5 stars
$11.99Chewy Price
$19.78Chewy Price
$11.39Autoship Price
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About This Item


  • High levels of nitrate can create unwanted algae growth and poor water quality, but this kit helps you to control it.
  • This kit tests nitrate levels ranging from 0 to 160 ppm in fresh or saltwater.
  • Designed for use in both fresh and saltwater aquariums.
  • Prevents unwanted algae growth in your aquarium.
  • Includes two bottles of the liquid test solution, two color cards, glass test tube and information on how to correct levels.

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Play Video: Learn More About API From Our Team of Experts
Learn More About API From Our Team of Experts

Help keep your aquarium in tip-top shape with API's Nitra-Zorb filtration pouch.

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About API Testing

Testing the Waters

For fish to thrive, their aquarium water must be similar to the water in their natural environment. Poor water quality can cause stress, illness and even the loss of your fish. Important water quality parameters include ammonia, nitrite, nitrate, and pH. These can vary over time, and they are invisible to the eye, which is why it is necessary to test weekly. Choose from a wide range of API testing options like the Freshwater Master Test Kit or 5-in-1 Test Strips to accurately evaluate your water.

Pressed for Time? Just Dip and Read

Simply dip an API test strip into your aquarium, swirl it twice, and then use the color-coded chart to determine if your water is within safe parameters or if adjustments are needed. That’s it! API test strips are available in a 5-in-1 version, which includes testing for pH, nitrite, nitrate, carbonate, and general hardness. Ammonia and pH test strips are also available so you can mix and match according to your needs.

The Scientific Approach

Get professional results from the comfort of your home with API test kits. Measure up to six parameters with API Master Test Kits, or pick and choose from a wide variety of individual test kits. Both types of kits come with test tubes and a laminated, calibrated color card. API test kits allow for numerous tests, making them an inexpensive way to help keep your aquarium water quality in check.

How to Correct Aquarium Water Parameters

Too Much Ammonia?

Ammonia is released into the water through gills, urine, uneaten food and more. API Ammo-Lock detoxifies it instantly.

Inappropriate pH Levels?

Fish require a specific pH level to thrive. Use API pH Down to lower freshwater aquarium water pH to the right level.

Too Much Nitrite?

Use API Quick Start to quickly consume nitrite and help maintain an active biological filter.

Nitrates Too High?

API Nitra-Zorb helps remove nitrate and other toxins that can be harmful to fish and lead to algae growth.

About API

The team at API has a passion for fish and understands the rewards and relaxation fishkeeping can bring. For almost 60 years, they have developed premium products with a focus on proven and effective results. API offers a range of testing kits, water conditioners and nutritionally superior fish foods. They are dedicated to making a better underwater world for the benefit of fish and those who keep them.

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Fish TypeBetta, Bottom Feeder, Cichlid...Betta, Bottom Feeder, Cichlid...Betta, Bottom Feeder, Cichlid...Betta, Bottom Feeder, Cichlid...Betta, Bottom Feeder, Cichlid...
Aquarium TypeSaltwater, FreshwaterSaltwater, FreshwaterSaltwater, FreshwaterSaltwater, FreshwaterSaltwater, Freshwater

Questions & Answers

2 Customer Questions

Can I accurately test my drinking water (city tap water) with this to check the nitrate levels in our drinking water?
Answer by ChewyMar 29, 2022
This kit can test the approximate nitrate levels in your drinking water.

How do we dispose of the reagent after we do the test? It has some safety warnings and I'm not sure how to dispose of it.
Answer by ChewyMar 01, 2021
We would recommend to dispose used tests fluid down the drain with running water. The tube may be disposed of in the trash receptacle.

ReviewsWrite a Review

Rated 4.6667 out of 5 stars
6 Ratings
Would recommend to a friend

6 Customer Reviews

Rated 5 out of 5 stars
By Rick on Oct 21, 2020
Top 1000 Contibutor

Absolutely necessary

Testing the pollutant levels of aquarium water is essential for maintaining the good health of your fish and plants, but regular testing of the Nitrate level is absolutely necessary. If you have an established tank or are cycling a new tank you need to monitor the Nitrate level on a regular basis. I was very pleased to find out that I could buy the individual Nitrate test kit. I have the big test kit but I needed just the Nitrate kit because it's the one I use the most and I used it all. I didn't want to buy the big kit again just to get the Nitrate. Unfortunately, the test uses 10 drops each of both solutions as opposed to 3 or 5 drops for most of the other tests.

Rated 5 out of 5 stars
By Doug on Jan 21, 2021

Best Method To Check Nitrates

Been using API Liquid Test Kits for some time, and find them very reliable.

Rated 5 out of 5 stars
By Demeter on Jun 29, 2020
Top 1000 Contibutor

Great test kit

I believe my niece misplaced one of the two bottles so I bought this as a replacement. Good to have it back and be able to keep an eye on the nitrates in my shrimp tanks.

Rated 4 out of 5 stars
By Pamala on Jun 22, 2018

When you just want one important test or to compare:

I have thew full API test knit but was afraid it was not accurate since my nitrates were way too high but my LFS had different readings. My test kit is good as I come up with the same results. After watching 2 FLS test my water, I realized they were doing it wrong! Now I trust my own findings.

Rated 4 out of 5 stars
By blessed on Apr 24, 2018

Good test kit, butt the bottles are extremely fragile.

Accurate results, but one of the bottles broke the first day I used it when it only fell like 7 inches. replacement bottles aren't too cheap either.

Rated 5 out of 5 stars
By Stella on Mar 29, 2018

great test kit

I have 3 aquariums that contain dirted, planted tanks. I need to test for the water levels to make sure the aquariums are biologically sufficient for both the plants and fish. This test kit is great and I really recommend it. I also like ordering from Chewy because the order comes fast and Chewy is a great company to deal with.