







🐠 Keep your tank thriving with precision water testing — don’t let your fish miss out!
The API GH & KH Test Kit is a professional-grade freshwater aquarium water testing solution that accurately measures general hardness and carbonate hardness. Designed for weekly use, it helps aquarists maintain optimal mineral balance and pH stability, preventing stress and loss in fish and plants. The kit includes two bottles of testing solution and capped test tubes, offering reliable, easy-to-use monitoring trusted by hobbyists for nearly six decades.



















| Customer Reviews | 4.7 out of 5 stars 5,784 Reviews |
R**O
helpful tool for maintaining a healthy tank environment
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!
A**S
Works well
Lots of tests…
S**.
Nothing Fishy!
A little water chemistry to help me get perfect espresso brewing water. Easy to use and understand.
V**V
I’m good
Pretty good testing kit I’ll give my pros and cons for the pros. This test kit is really good for trying to calculate your GHAKH if you’re keeping pets that need it personally for me it took a couple days to actually get a good reading of GHNK because it doesn’t have a color chart another pro is that they give you a number chart of how many drops in degrees your education should be a pretty good product. You’ll understand it after for the cons is that it’s really confusing at first. I want to say it’s the best beginner products unless you really know about your water chemistry but for anything else is pretty good
M**Z
Slightly tricky if not annoying ,on first use.
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.
D**E
Understanding hardness
I found the test strips difficult to read so I am happy I got this test set. Very simple and straightforward instructions.
H**R
Worth the money if you have shrimp and need to understand the causes of a high water PH
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.
D**N
API GH and KH Test Kit is fairly easy to use and interpret, and it seems accurate
The API GH and KH Test Kit is fairly easy to use, and it is easy to determine the results, and the results seem accurate. The API GH and KH Test Kit comes with 2 test tubes. You fill a test tube up to the measurement line with the water to be tested. Then you place a drop of the GH or KH solution (depending on which you are testing for) in the water, then put the cap on the test tube and invert it a few times, and you look at the color of the water in the test tube. You repeat the process of adding a single drop of the solution and inverting the tube, keeping track of the cumulative number of drops of solution, until the water changes to the designated color. The number of drops of the test solution that it took to cause the water color to change is the degrees of carbonate level or hardness. So if it took 4 drops of the KH solution to get the water color to change, then the KH level is 4 dKH, etc. I just have 2 minor complaints about this test kit. My biggest complaint is that the caps for the test tubes leak a little bit, so I have to wrap a paper towel around the test tube before I invert it. My only other complaint is that it takes a little bit of effort to fill the test tube exactly to the measurement line, so I use a dosing syringe to draw the water to be tested.