Product Information

API GH & KH Test Kit – Professional liquid aquarium test kit for measuring General Hardness (GH) and Carbonate Hardness (KH) in freshwater. Essential for monitoring pH stability, RO water remineralization, shrimp keeping, planted aquariums, African Cichlids, Discus, and overall water chemistry management.

General Hardness refers to the concentration of dissolved minerals such as calcium and magnesium in the water. Monitoring GH helps aquarists provide the ideal water conditions required by specific fish species and aquatic plants.

Tests Carbonate Hardness (KH)

Carbonate Hardness measures the water’s buffering capacity and ability to resist sudden pH fluctuations. Maintaining proper KH levels helps support stable pH conditions and reduces the risk of harmful pH swings.

Supports Healthy Fish and Plant Growth

Different fish species require different hardness levels to thrive. Regular testing allows aquarists to create water conditions that support healthy fish, vibrant plants, and overall aquarium stability.

Helps Maintain Stable Water Chemistry

Monitoring GH and KH levels is important when keeping sensitive fish species, breeding fish, planted aquariums, or adjusting water parameters using RO water or specialized additives.

Simple and Accurate Testing

The liquid reagent testing method provides accurate and dependable results. The easy-to-follow instructions make testing quick and convenient for both beginner and experienced aquarium hobbyists.

Ideal for Freshwater Aquariums and Ponds

This test kit is suitable for freshwater tropical aquariums, planted tanks, breeding setups, shrimp aquariums, and ornamental ponds where water hardness plays a critical role in aquatic health.

Why GH & KH Matter

Many common aquarium problems are actually related to water hardness:

• Unstable pH
• Shrimp losses
• Breeding difficulties
• Poor plant growth
• Difficulty maintaining specific fish species
• pH crashes
• Fish stress after water changes

GH and KH testing allows hobbyists to understand these issues before they become serious problems.

Ideal For

• Shrimp Aquariums
• Planted Aquariums
• Discus Tanks
• Betta Aquariums
• African Cichlid Aquariums
• Flowerhorn Aquariums
• Community Aquariums
• Breeding Tanks
• RO Water Systems
• Freshwater Aquariums
• Marine Aquariums

What’s Included

• GH Test Reagent
• KH Test Reagent
• Test Tube
• Instructions

Key Benefits

• Measures General Hardness (GH) and Carbonate Hardness (KH).
• Helps maintain stable pH and water chemistry.
• Supports healthy fish, shrimp, and aquatic plants.
• Useful for freshwater aquariums and ponds.
• Accurate liquid-based testing system.
• Easy-to-use for routine water parameter monitoring.
• Ideal for planted tanks, breeding tanks, and community aquariums.

Country of Origin – USA

Expert Recommendation from Something Fishy

If you use RO water, keep shrimp, maintain planted aquariums, breed fish, or struggle with unstable pH, the API GH & KH Test Kit is one of the most valuable water testing tools you can own.

At Something Fishy, we often find that hobbyists focus on pH while overlooking KH—the parameter that largely determines pH stability.

Understanding GH and KH can solve many aquarium problems that water conditioners and medications cannot.