Aquarium CO2 Injection Calculator
CO2 Level from pH & KH
Calculate dissolved CO2 concentration from pH and carbonate hardness
CO2 Tank Duration
Estimate how long a CO2 cylinder will last
Formula
CO2 (ppm) = 3.0 × KH (dKH) × 10^(7 - pH)
Frequently Asked Questions
How much CO2 do I need for a planted aquarium?
Most planted tanks target 20-30 ppm of dissolved CO2 during the photoperiod. Start with 1 bubble per second for tanks under 30 gallons and increase gradually while monitoring pH and fish behavior.
How do I measure CO2 in my aquarium?
The most common methods are: 1) pH/KH chart (measure pH and KH, use the formula CO2 = 3 × KH × 10^(7-pH)), 2) Drop checker with 4 dKH reference solution (green = ~30 ppm).
When should I run CO2 injection?
Run CO2 during the photoperiod (when lights are on) and turn it off 30-60 minutes before lights off. Use a solenoid valve on a timer for automatic control. CO2 is not needed when lights are off.
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