API GH & KH Test Kit Combo

Regular price
Sale price
Regular price
Sold out
Unit price

Maximum quantity in stock reached.

  • Measures Dissolved Minerals in Water
  • Quickly and Accurately Reads GH and KH Levels
  • Easy to Read Instructions

The API GH and KH test kit tests the levels of carbonate hardness and general hardness in the aquarium. KH or carbonate hardness in high enough levels prevents pH from changing rapidly and maintains a healthy system. GH or general hardness is a measurement of how many dissolved minerals are present in your water. Depending on the fish being kept would determine how much hardness should be present in the water. Guppies, Mollies, Platies, Swordtails, Goldfish, African Cichlids and more like high mineral content as it matches their natural habitat. Ensure proper levels of both KH and GH in your aquarium with this test kit.

Customer Reviews

Based on 70 reviews
Anonymous (Lake Saint Louis, MO, US)
GH & KH Test Kit

I prefer drop kits over test strips. Quick Shipping.

Jessica H. (Springfield, IL, US)
Easy to monitor water hardness

This product is very easy to use since the visual cue is a stark color change. KH test will turn the water from blue to yellow, GH test will turn the water GREEN, like green green. This is an important test to keep on hand if you are keeping any stock that really prefers a specific range of hardness. I also recommend getting a small pack of glass stirring rods so you don't have to cap and shake every time.

Dave T.
As Easy As..

Simple to do and lets you know just what is going on in your aquarium.

John W. (Auburn Hills, MI, US)
API hardness test kit

Like all products I’ve used from API it works great.
As for Aquarium Co-op, the service is still amazing!

Marilynn C. (Honolulu, HI, US)
Buffering & GH test

As a new fish keeper (almost!), I was using the Aquarium Co-Op test strips to check the water parameters as I was cycling my first tank and was surprised to find a fairly low KH reading … so to not harm my future fish, I decided to order the API liquid test to double check and was impressed that both methods yielded the same result. Gave me confidence to go ahead. I would definitely recommend both products.