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CO₂ Bubble Rate Calculator

Calculate CO2 concentration from KH and pH values.

CO2 Bubble Count Calculator

Calculate CO2 from KH and pH values

Formula

CO2 (mg/L) = 3.0 × KH × 10^(7.0 - pH)

How to Use

  1. 1
    Test your waterMeasure KH (carbonate hardness) and pH using liquid test kits for accuracy.
  2. 2
    Enter KH and pHInput the measured KH in dKH and pH value into the calculator.
  3. 3
    Read CO₂ levelThe calculator shows your CO₂ concentration in mg/L (ppm).
  4. 4
    Adjust if neededAim for 20-30 ppm CO₂ for optimal plant growth without harming fish.

Frequently Asked Questions

What is the ideal CO₂ level for a planted tank?

20-30 mg/L (ppm) is ideal. Below 20 ppm, plants may not thrive. Above 30 ppm, fish may show signs of stress.

How does KH affect CO₂ readings?

CO₂ concentration is calculated from the relationship between KH and pH. Higher KH at the same pH means more CO₂ is dissolved.

Why is my drop checker yellow?

A yellow drop checker indicates CO₂ is above 30 ppm, which may be too high for fish. Reduce your bubble rate or increase surface agitation.

Can I use CO₂ with a low-tech tank?

Yes, but low-tech tanks usually rely on natural CO₂ from fish and organic matter. Injected CO₂ is typically used in high-light, high-tech setups.