CO₂. Uptake. Acceleration. Smarter cultivation starts with better air.
CO₂ Supplementation Calculator
Welcome to the CO₂ Supplementation Calculator & Planner
This easy-to-use tool helps you figure out how much CO₂ your plants need at each stage of growth — and turns it into a clear daily schedule with calendar dates you can follow.
Getting Started is Simple:
- Enter your grow room size and how you deliver CO₂
- Set the number of days and target ppm for each stage
- Click Create CO₂ Plan to generate your schedule
- Save it to your Grow Journal, and export it if needed
What This Tool Helps You Plan:
- Grow Stage Transitions – Automatically adds each stage to your grow calendar with start dates and durations
- CO₂ Tank Refills – Estimates when you’ll need a refill based on your tank size and injection rate
- Daily CO₂ Injections – Creates reminders if you inject multiple times per day
Note: Several fields in this tool auto-fill with recommended defaults to help beginners get started quickly. All values are fully editable, so more advanced users can customize every part of the plan.
Need all this in your calendar? Click “Save to Journal” and then export to Google Calendar or ICS.
Step 1: Start by entering the length, width, and height of your sealed grow space (measured in feet) in the following 3 boxes below. If you're using a tent, use the tent dimensions. If you're using a closet or room, use those dimensions.
Step 2: Choose the current plant growth stage. We'll automatically suggest a CO₂ ppm level that works best for this phase. You can adjust it if you have a specific target in mind.
Step 3: This is the parts-per-million (ppm) level of CO₂ you want to reach in your grow space. A recommended value is pre-filled based on the selected growth stage, but you're free to adjust it manually if needed.
Step 4: Enter the injection rate of your CO₂ emitter or regulator (measured in liters per minute). This helps us estimate how long each injection will need to run. It’s usually listed on your CO₂ regulator or emitter. If you're not sure, 10 L/min is a good starting point.
Step 5: Input the size of your CO₂ tank in pounds (lbs). A standard tank holds 20 lbs, which is about 9000 grams of CO₂. This helps calculate how many injections your tank can provide before needing a refill.
Optional Enhancements: These settings help you better estimate injection timing and cost, but they aren't required to generate your CO₂ schedule. Great for power users or cost tracking.
Step 8: Review and adjust the timeline for each grow stage (Vegetative, Early Flower, Peak Flower, Ripening). We auto-fill the number of days and CO₂ levels based on common growing practices, but feel free to edit these if you have a custom schedule.
Grow Stages (Timeline) ℹ️ More info
Grow Journal
Track your environment and CO₂ planning across your grow stages. The Grow Journal helps you stay organized and efficient.
How This Works
This calculator estimates the amount of CO₂ (in grams) needed to reach your target ppm in a sealed space. Use it to plan CO₂ injections safely and efficiently.
Formula
Grams CO₂ = (Volume in ft³ × Target ppm × 0.0018)
Note: 0.0018 is a conversion factor for ppm in ft³ to grams of CO₂.
Tips for Use
- Only inject CO₂ when lights are on
- Keep room sealed when supplementing
- Monitor with a CO₂ controller for safety
- Target 1000–1200 ppm during flower for best results
Frequently Asked Questions (FAQ)
1. Do I really need CO₂ supplementation?
If you're growing in a sealed room or tent with strong lighting, CO₂ can significantly boost growth and yields — especially during flowering. It's optional, but highly effective for advanced results.
2. How many CO₂ injections per day should I use?
Start with 1 injection per day, shortly after lights turn on. This is simple and effective. As you gain experience, you can split into 2–3 smaller doses per day for more consistent levels.
3. When should I inject CO₂?
Only inject CO₂ when lights are on. Plants only absorb CO₂ during photosynthesis — injecting at night wastes gas and may harm your environment.
4. What’s a good CO₂ ppm target for each stage?
- Seedling / Clone: 300–600 ppm
- Vegetative: 800–1000 ppm
- Early Flower: 1000–1200 ppm
- Peak Flower: 1200–1500 ppm
- Ripening / Flush: 400–600 ppm
5. How do I know when to refill my CO₂ tank?
The calculator estimates this for you based on your tank size, injection rate, and how often you inject. It helps avoid running out mid-grow.
6. What’s the formula used to calculate CO₂ needed?
Grams CO₂ = Room Volume (ft³) × Target ppm × 0.0018
This formula tells you how much CO₂ to inject to reach your goal ppm.
7. Can I save my CO₂ plan and use it later?
Yes! Click “Save to Journal” to store your plan. You can also export it to Google Calendar or download as an ICS file.
8. Do I need a CO₂ controller?
Not required, but helpful. Controllers automate injections and stabilize ppm. Great for safety and consistency as you scale up.
9. Is this calculator safe for beginners?
Yes — it’s designed with default values, editable fields, and step-by-step guidance. Beginners can use it confidently without needing advanced gear.
10. Where can I learn more?
Visit the Grow Journal or Learning Center at GroHaus for tutorials, tools, and tips.
Tool by GrōHaus — helping growers optimize air, light, and yield through precision CO₂ control.