🌿 CO2 Dosing Calculator for Planted Tanks
Calculate the ideal CO2 injection rate for your planted freshwater aquarium.
20-30 ppm optimal. Above 35 ppm harmful to fish.
Results
CO2 Injection Rate
—
Bubbles Per Second — adjust with drop checker
Target Level
—
Estimated Usage
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Tank Duration
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BPS = (Gallons ÷ 10) × Light factor × Plant density × Target adjustment
Light factors: Low=1, Med=1.5, High=2.5
Use a drop checker to verify — lime green = 30 ppm (ideal)
Light factors: Low=1, Med=1.5, High=2.5
Use a drop checker to verify — lime green = 30 ppm (ideal)
CO2 for Planted Aquariums
Carbon dioxide is the most important nutrient for aquatic plants. Without adequate CO2, plants can't fully utilize light and fertilizers, leading to algae problems and poor growth.
CO2 Level Guide
| Level | CO2 ppm | Drop Checker Color |
|---|---|---|
| Too Low | < 15 ppm | Blue |
| Optimal | 20–30 ppm | Lime Green |
| Dangerous | > 35 ppm | Yellow |
Setup Tips
- Start CO2 1-2 hours before lights come on
- Turn off CO2 when lights go off (fish don't need it at night)
- Use an inline diffuser or reactor for best dissolution
- A drop checker gives a reliable real-time CO2 reading
- 5lb CO2 tanks last 2-4 months for most setups