KH (Alkalinity) Converter – dKH, ppm & meq/L Calculator for Ponds & Reef Aquariums
Professional alkalinity conversion tool for koi ponds, freshwater systems, and marine reef aquariums. Instantly convert KH values and understand water stability in real time.
What is KH (Carbonate Hardness)?
KH (Carbonate Hardness), also known as alkalinity, measures water’s ability to resist pH change. It is essential for stable aquatic environments in ponds and reef aquariums. Without stable KH, water becomes chemically unstable, leading to dangerous pH swings that stress fish and coral systems.
Why KH Stability Matters
KH (Carbonate Hardness), also known as alkalinity, measures water’s ability to resist pH change. It is essential for stable aquatic environments in ponds and reef aquariums.Without stable KH, water becomes chemically unstable, leading to dangerous pH swings that stress fish and coral systems.
Why KH Stability Matters
- Prevents sudden pH crashes in pond systems
- Supports biological filtration and nitrifying bacteria
- Improves coral growth and calcification in reef tanks
- Reduces stress and disease risk in aquatic life
KH Conversion Formulas
1dKH = 17.848 ppm (CaCO₃) 1ppm = 0.056 dKH1 meq/L = 2.8 dKH
Ideal KH Levels
Pond / Koi Systems 5–8 dKH = stable and optimal < 3 dKH = high pH crash risk > 12 dKH = excessively hard water
Reef Aquariums 7–12 dKH = optimal coral growth < 7 dKH = coral stress risk > 12 dKH = precipitation risk
Common KH Mistakes
- Confusing ppm and dKH readings Changing KH too quickly Ignoring KH in high biological load systems How to Raise KH Safely Use sodium bicarbonate (baking soda)Increase gradually over 24–48 hours Always monitor pH alongside KH