API Freshwater Aquarium Master Test Kit, 800 count - Chewy.com

API Freshwater Aquarium Master Test Kit, 800 count

Rated 4.6081 out of 5 stars
$35.98Chewy Price
$50.48Chewy Price
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About This Item


  • Specifically designed to measure, modify and balance the conditions of freshwater aquariums.
  • Measures freshwater pH, high range pH ammonia, nitrate and water hardness.
  • Includes 4 test tubes, a holding tray for testing bottles and a test tube rack.
  • Helps protect your finned friends from toxic water conditions.
  • Easy-to-follow instructions, simply compare your results to the color card.

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

To help lower your aquarium's pH level check out API's pH Down. If you need to raise the pH level then API's pH Up water treatment is just what you need.
Test your aquarium's water with API's replacement test tubes.
Compatible with API's Filstar xP4 Filter.

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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Questions & Answers

18 Customer Questions

Does this kit give us what is needed to correct the problem it discovers or do we purchase that separately?
Answer by ChewyNov 04, 2018
This kit is specifically designed to measure, modify and balance the conditions of freshwater aquariums.

How many water tests can you get out of one kit?
Answer by ChewyJul 28, 2017
This kit includes 4 test tubes with snap-tight caps.

Will this test kit let me know if there is chlorine present? I'm a real noobie.
Answer by ChewySep 13, 2021
This test kit does not test for chlorine level. This kit measures the 4 most important levels in freshwater aquariums quickly and accurately, including pH, high range pH, ammonia, nitrite, and nitrate.

What's the difference between "fresh water pH", and "high range pH"?
Answer by ChewyJun 19, 2019
The pH Test will be able to read a pH level between 6.0 to 7.6. When keeping livebearers, goldfish, African Cichlids or marine fish & invertebrates, the High Range pH Test should be used. High Range pH Test will be able to read a pH level between 7.4 to 8.8.

ReviewsWrite a Review

Rated 4.6081 out of 5 stars
148 Ratings
Would recommend to a friend

148 Customer Reviews

Rated 5 out of 5 stars
By Jay on May 7, 2023

Great kit for the average aquarium hobbyist

All you need to keep your tank clean and fresh without breaking your bank. Easy to use with clear instructions for beginners. This all in one kit helped to clear up some of the confusion around water treatment products when it comes to maintaining balance in your tank. I guess they've updated the kit a bit too, as it now securely holds your test tubes in place during storage.

Rated 5 out of 5 stars
By Justin on Jan 20, 2023

Easy to use test kit

This is a great kit overall, especially like the storage container. I do have two wishes though. Since each test has slightly different instructions, I wish they were printed on the bottle instead of in the booklet (yes, I know there are too many languages for it to fit...). Also wish the kit included hardness test.

Rated 5 out of 5 stars
By ApiKit on May 5, 2023

Absolutely Perfect

Worth the money and will last you for ages! Shipping was quick and efficient as well.

Rated 5 out of 5 stars
By MrsP on Jan 4, 2023

Great, Reliable Test Kit

I use these test kits both at home and with my AP Chemistry students. They have a semester-long project in which they research and perform a fishless cycle. After the cycle, they choose what they want in the tank. The only rule: Everything has to live in peace and harmony, (More research!). The test kits are fantastic and accurate.

Rated 5 out of 5 stars
By April on Sep 4, 2022

Super helpful

I love this test kit, It is compact and easy to store. A really good option for someone with multiple tanks for a fishkeeping hobby.

Rated 5 out of 5 stars
By KimR on Aug 23, 2022

Great product

Easy to use and will last longer than the strips so a better value for money. I just wish it came with a test for chlorine also

Rated 4 out of 5 stars
By Jess on Jul 16, 2022

Easy instructions!

The instructions are simple and quick! The only problem is it's a little difficult to get a perfectly accurate reading with the color chart. Also a little on the expensive side.

Rated 5 out of 5 stars
By Michelle on Jun 3, 2022

Would Recommend

Very organized product that provides extensive results with simple instructions and testing. I also enjoyed that it offered ways to correct things if something was wrong!

Rated 5 out of 5 stars
By Lauren on Feb 25, 2022

A must have for fish keepers

I have been in the aquarium hobby for more than a decade. If you are going to keep fish then you have to know the nitrogen cycle. It is the single most important thing. This test kit is a must have. It is the best thirtyish dollars you will ever spend. This test kit allows you to monitor your ammonia, nitrite, nitrate and pH levels. When setting up a tank you will need to test daily. Once the tank has been running for a while and the nitrogen cycle has happened in full you can test less frequently. Yes you can but the test strips to tell you everything this kit will do but the strips are much more expensive in the long run.

Rated 5 out of 5 stars
By Autumn on Dec 5, 2021

Easy to use

Excellent! There are however warning on some bottles about damage if in contact with skin, eyes, inhaling, and accidental ingestion. So just be careful.