Free aquarium CO2 calculator. Calculate optimal bubble rate (BPS) for your planted tank based on volume and plant density. Target PPM recommendations included.
Plants use CO2 for photosynthesis. In low-light tanks, natural CO2 from fish waste is sufficient. In high-light tanks with dense plants, supplemental CO2 increases growth. Safe target range is 15–25 ppm CO2.
BPS measures CO2 injection rate. 1 BPS = 1 bubble per second. Typical rates are 1-3 BPS for small tanks, 3-5 for medium, 5+ for large tanks. Adjust based on plant growth and CO2 levels.
This calculator uses standard guidelines for CO2 injection. Actual needs depend on plant density, light intensity, and water parameters. Use a CO2 test kit to verify levels.
Options include pressurized cylinders (best for large tanks), DIY yeast systems (budget-friendly), and liquid CO2 (convenient but expensive). Choose based on tank size and budget.
Properly dosed CO2 (15–25 ppm) is safe for fish. Above 25 ppm fish can show stress; above 30 ppm is often lethal for sensitive species. Monitor pH and CO2 levels. Use a drop checker to verify CO2 concentration. Ensure adequate aeration.