API KH Test Kit 

Maintain stable water chemistry and support a healthy aquarium with the API KH (Carbonate Hardness) Test Kit.

This easy to use test kit measures carbonate hardness (KH), also known as alkalinity a key parameter that helps stabilize pH and maintain a balanced environment for fish, corals, and invertebrates.

With simple liquid testing and clear results, this kit makes it easy to monitor alkalinity and prevent sudden swings that can stress or harm your aquarium.

What It Tests

• Carbonate Hardness (KH / Alkalinity)

Why It Matters

KH plays a critical role in maintaining stable pH levels in your aquarium.
Low alkalinity can lead to dangerous pH swings, while stable KH helps create a consistent and healthy environment for your livestock.

For reef tanks, proper alkalinity is essential for coral growth and long term system stability.

Perfect For

• Reef aquariums (soft coral, LPS, and SPS systems)
• Freshwater aquariums requiring pH stability
• Monitoring water chemistry and preventing pH swings
• Beginner and intermediate hobbyists

What’s Included

• KH test solution
• Glass test tube with cap
• Color comparison chart
• Step by step instructions

Pro Tip

For complete reef monitoring, pair this test kit with calcium and phosphate testing to maintain balanced parameters and support coral health.