Colombo KH Test

If your pH swings up and down, low KH is often the cause. The Colombo KH Test measures carbonate hardness, helping you keep your pond water stable and safe for koi.

KH – carbonate hardness – acts as a buffer. It prevents sudden pH crashes that can stress or harm fish. Regular testing lets you correct levels before problems develop.

Why KH matters in a pond

• Supports stable pH levels
• Protects fish from sudden water changes
• Helps your biological filter work efficiently
• Essential during heavy feeding and warm weather

In koi ponds, consistent KH is key to long-term stability. If levels drop too low, your filter bacteria can struggle and pH can fall quickly.

What’s included

• Liquid drop test reagents
• Test tube
• Colour comparison chart
• Instructions

Clear colour changes make readings straightforward, whether you’re testing routinely or checking after heavy rain or water changes.

When to test KH

• At the start of the season
• After significant rainfall
• When increasing feeding
• If pH readings fluctuate

Good practice & safety

• Rinse test equipment with pond water before and after use.
• Store reagents in a cool, dark place.
• Keep chemicals out of reach of children and pets.