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API Water Test Kit

4.7 out of 5 stars 21,110 ratings

List Price: $47.39 Details
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Enhance your purchase

  • Contains one (1) API FRESHWATER MASTER TEST KIT 800-Test Freshwater Aquarium Water Master Test Kit, including 7 bottles of testing solutions, 1 color card and 4 glass tubes with cap
  • Helps monitor water quality and prevent invisible water problems that can be harmful to fish and cause fish loss
  • Accurately monitors 5 most vital water parameters levels in freshwater aquariums: pH, high range pH, ammonia, nitrite, nitrate
  • Designed for use in freshwater aquariums only
  • Use for weekly monitoring and when water or fish problems appear
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  • API Water Test Kit
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  • API TEST KIT, Different styles available, Monitors water quality and helps prevent invisible problems that can be harmful to
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From the manufacturer

Test Test Test Test Test Test
Too much nitrites?
Too much ammonia?
Inappropriate pH levels?
Too much nitrates?
Too much phosphates?

Product Description

Most water problems are invisible to the eye. Quickly measure and modify the six aquarium levels that are most important to the health of your freshwater fish with the API FRESHWATER MASTER TEST KIT. To stay healthy and thrive, fish need properly balanced levels of ammonia, pH, high range pH, nitrite and nitrate. These levels can change rapidly and create harmful conditions when fish waste, uneaten food or other organic matter accumulate, or when untreated water is added. If left uncorrected, all of these can be harmful or even fatal to fish, with consequences such as reduction of oxygen, increase in stress and higher risk of disease. The API FRESHWATER MASTER TEST KIT measures these six parameters with scientific accuracy and provides professional results. It comes with four glass test tubes, a holding tray, test tube rack and computer calibrated, laminated color card. Just fill the test tubes, add the test drops and compare results to the color card. Then follow the recommendations on the card if action is required. With API Aquarium products, it’s easy to keep a beautiful saltwater, freshwater or reef aquarium. For over 50 years, API has been creating innovative, research-driven solutions that make it easier to care for your fish and aquarium. API Aquarium Treatment Supplies are designed to work in conjunction with each other to provide best results to control algae, promote healthy bacterial growth and help control and cure fish diseases and conditions such as ich and fin rot. They work to provide a safe, hospitable environment for fish such as tropical community fish, cichlids, goldfish and more. With API, you can spend more time admiring your fish, and less time scrubbing your tank. Make sure to use all products as directed in order to ensure the best results.

Product details

  • Is Discontinued By Manufacturer ‏ : ‎ No
  • Product Dimensions ‏ : ‎ 9.13 x 3.5 x 4.63 inches; 1.15 Pounds
  • Item model number ‏ : ‎ 34
  • Date First Available ‏ : ‎ June 20, 2004
  • Manufacturer ‏ : ‎ Mars Fishcare
  • ASIN ‏ : ‎ B000255NCI
  • Country of Origin ‏ : ‎ USA
  • Domestic Shipping: Item can be shipped within U.S.
  • International Shipping: This item is not eligible for international shipping. Learn More
  • Customer Reviews:
    4.7 out of 5 stars 21,110 ratings

Product guides and documents

Important information

Safety Information

Please Read Instructions Before Use


Includes Four Test Tubes, Caps, Computer-Analyzed Laminated Color Charts, Instructions


Follow the instructional booklet directions for individual testing of each water parameter, and test weekly for best results.

Customer Questions & Answers

Customer reviews

4.7 out of 5 stars
4.7 out of 5
21,110 global ratings

Top reviews from the United States

Reviewed in the United States on January 20, 2017
Style: FreshwaterVerified Purchase
Customer image
5.0 out of 5 stars Accurate test that takes around 10 minutes to do
By Ryott on January 20, 2017
I recently bought my first fish tank, [[ASIN:B013BXDXTC Tetra ColorFusion 20 Gallon Aquarium Kit]], and quickly learnt about the importance of testing the water. In case you do not know, a new fish tank needs to go through a cycle where the waste becomes ammonia (dangerous for fish); then, bacteria will grow and convert it into nitrite (also poisonous); and then additional bacteria will grow and convert it into nitrate (not dangerous). To ensure that your fish survive in the long term, you need to monitor these three parameters and make sure that the ammonia and nitrite do not remain high for too long.

I decided to buy this kit so I can do tests every two days, as I read that it is more accurate and inexpensive than using strips. Overall, I am very happy with it. Every test I do takes just a few drops. The manufacturer claims 800+ tests, but be careful that is the total number (adding all the different tests together). If you look at just one type of test, like nitrate, the one that requires the most drops, you will be able to do 50-60 tests (as another reviewer has calculated). Most of the tests are very easy to do, with the exception of nitrate, that requires shaking the bottle for 30 seconds and the water sample for 1 minute, and it is somehow tiring. I found running all the tests took me around 10 minutes. I have taken a video so you can get an idea of the "effort involved".

Overall, I am very happy with this kit. Over the last few days I have seen the ammonia climbing, then nitrite and now nitrate, so I can perfectly understand what is going on in my tank!
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535 people found this helpful
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Reviewed in the United States on March 4, 2019
Style: FreshwaterVerified Purchase
140 people found this helpful
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Reviewed in the United States on March 19, 2018
Style: FreshwaterVerified Purchase
48 people found this helpful
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Top reviews from other countries

Brian R J Glover
4.0 out of 5 stars Easy to Use
Reviewed in the United Kingdom on June 8, 2014
Style: SaltwaterVerified Purchase
44 people found this helpful
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2.0 out of 5 stars Not convinced
Reviewed in the United Kingdom on December 28, 2020
Style: SaltwaterVerified Purchase
2.0 out of 5 stars Became VERY innacurate after 2 months - strange black liquid clumps in and around bottle.
Reviewed in the United Kingdom on August 29, 2018
Style: SaltwaterVerified Purchase
2 people found this helpful
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Attila Szabo
1.0 out of 5 stars Inaccurate - avoid - nothing master about it
Reviewed in the United Kingdom on September 22, 2021
Style: ReefVerified Purchase
3.0 out of 5 stars If you have corals you will also need the Reef test kit
Reviewed in the United Kingdom on February 13, 2020
Style: SaltwaterVerified Purchase