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API

API GH & KH TEST KIT Freshwater Aquarium Water Test Kit, 2.5 oz.

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Arrives Saturday, May 16
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Size: 2.5 oz


Style: GH & KH


Features

  • Contains one (1) API GH & KH TEST KIT Freshwater Aquarium Water Test Kit, including 2 bottles of testing solution and 2 test tubes with cap
  • Helps monitor water quality and prevent invisible water problems that can be harmful to fish and plants and cause fish loss
  • Accurately measures GH & KH in freshwater aquariums
  • Water hardness is a measure of the dissolved mineral content of water and should match fish natural habitat to prevent fish stress and keep them healthy
  • Use for weekly monitoring and when water or fish problems appear

Description

Keep your fish healthy and thriving by testing your aquarium water's GH levels regularly with this easy-to-use API GH & KH TEST KIT for freshwater aquariums. Testing water parameters weekly helps prevent invisible water problems that can be harmful to fish. Water hardness is a measure of the dissolved mineral content of water. There are two types: the general hardness (GH) and carbonate hardness (KH). When keeping freshwater fish and plants, the GH and the KH of aquarium water should match their natural habitat. The API GH & KH TEST KIT helps aquarists duplicate the natural habitat of their fish, as well as detect low KH levels, which can lead to rapid and wide pH shifts, stressing fish. API GH & KH TEST KIT contains KH test bottle, GH test bottle, instructions and two capped test tubes. With API aquarium products, it’s easy to keep a beautiful saltwater, freshwater or reef aquarium. For almost 60 years API has developed premium solutions with proven and effective results for your family and ours. API offers a range of testing kits, water conditioners, and nutritionally superior food, because we’re dedicated to making a better underwater world. They work to provide a safe, hospitable environment for fish such as tropical community fish, cichlids, goldfish and more. At API, we understand the rewards and relaxation of fishkeeping because we have a passion for fish too.

Is Discontinued By Manufacturer ‏ : ‎ No


Product Dimensions ‏ : ‎ 2.75 x 1.63 x 5.13 inches; 2.5 ounces


Item model number ‏ : ‎ 58


Department ‏ : ‎ Unisex-Adult


Date First Available ‏ : ‎ June 20, 2004


Manufacturer ‏ : ‎ Mars Fishcare


Best Sellers Rank: #2,120 in Pet Supplies (See Top 100 in Pet Supplies) #3 in Aquarium Test Kits


#3 in Aquarium Test Kits:


Customer Reviews: 4.7 4.7 out of 5 stars (5,829)


Item Weight: 2.5 ounces


Department: Unisex-Adult


Manufacturer: Mars Fishcare


Item model number: 58


Date First Available: June 20, 2004


Item Package Dimensions L x W x H: 5 x 2.83 x 1.73 inches


Item Dimensions LxWxH: 2.75 x 1.63 x 5.13 inches


Item Weight: 2.5 Ounces


Brand Name: API


Target Audience Keyword: Fish


Directions: It is necessary to test the GH and KH to monitor water quality and prevent stressful conditions.


Model Name: GENERAL/CARBONATE HARDNESS KIT


Color: DAA


Size: 2.5 oz


Material: Plastic


Number of Items: 2


Style: GH & KH


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Saturday, May 16

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • helpful tool for maintaining a healthy tank environment
Size: 2.5 oz Style: GH & KH
I recently started using the API GH & KH Test Kit for my freshwater aquarium, and I must say it has been an incredibly helpful tool for maintaining a healthy tank environment. Here’s a detailed review based on my experience: **Ease of Use:** The test kit is very straightforward and user-friendly. The included instructions are clear and easy to follow, even for beginners. Testing both General Hardness (GH) and Carbonate Hardness (KH) takes just a few minutes, and the color changes in the water make it easy to get accurate results. **Accuracy:** The API test kit provides reliable and consistent readings. I compared the results with a digital meter, and they matched up perfectly. Knowing the GH and KH levels helps me adjust my water chemistry for optimal conditions, especially for sensitive fish like cichlids and shrimp. **Functionality:** Having a tool that measures both GH and KH in one kit is incredibly convenient. GH helps monitor essential minerals for fish health, while KH is crucial for stabilizing pH levels. This kit makes it easy to detect changes early, helping prevent pH swings or stress in my fish. **Value for Money:** For the price, you get a high-quality, reliable kit that will last quite a while. The included bottles have enough solution for numerous tests, making it a cost-effective option for regular water monitoring. **Overall Impressions:** The **API GH & KH Test Kit** is a must-have for any freshwater aquarium enthusiast. It’s easy to use, highly accurate, and helps ensure your water parameters are within the right range for your fish and plants to thrive. I highly recommend it for hobbyists of all experience levels. **Rating: 5/5** Reliable, accurate, and easy-to-use water testing for a healthy aquarium! ... show more
Reviewed in the United States on December 17, 2024 by Renato

  • Works well
Size: 2.5 oz Style: GH & KH
Lots of tests…
Reviewed in the United States on March 31, 2026 by Angel Eyes

  • keeps track of KH and GH
Size: 2.5 oz Style: GH & KH
This is my second kit to check my goldfish tank for KH and GH. Simple, inexpensive and more accurate than strips.
Reviewed in the United States on May 4, 2026 by Mr. Fix-it

  • Nothing Fishy!
Size: 2.5 oz Style: GH & KH
A little water chemistry to help me get perfect espresso brewing water. Easy to use and understand.
Reviewed in the United States on March 2, 2026 by Steve W.

  • Slightly tricky if not annoying ,on first use.
Size: 2.5 oz Style: GH & KH
Well it finally arrived,a bit diferent to use than my other full API freshwater kit. The one drop and shake and so on to get the GH and KH results is slightly tricky if not annoying at first compared to the simple direct drop counting and instant results of the full kit. In they end, quite pleased once you get the hang of it and get the needed results. ... show more
Reviewed in the United States on February 28, 2026 by Mr. Michael Rodriguez

  • Works as Expected
Size: 2.5 oz Style: GH & KH
Very easy test and important. Comes with test tube.
Reviewed in the United States on March 2, 2026 by K. Axtell

  • Accurate tests for a good price
Size: 2.5 oz Style: GH & KH
Easy to use and easy to read
Reviewed in the United States on April 26, 2026 by Amazon Customer

  • Worth the money if you have shrimp and need to understand the causes of a high water PH
Size: 2.5 oz Style: GH & KH
I have shrimp, so this was important to have when understanding my water parameters. Its easy enough to figure out the tests as per the instructions, but the results are sometimes difficult to interpret. The look of the test color is sometimes unclear, but thats when I add another drop of the test liquid to make sure I know for sure what color Im seeing. Its important to not touch the chemicals to your skin. The bottles are a decent size and will last me a good amount of time. Worth the money if you have a species thats sensitive to hard water or if you're trying to determine the cause of a high PH. ... show more
Reviewed in the United States on March 2, 2026 by Heather

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