The formula to calculate the amount of CO2 needed is:

\[ \text{CO2 Needed (cu.ft.)} = \text{Width} \times \text{Length} \times \text{Height} \times \left( \frac{\text{Desired CO2 Level (ppm)}}{1,000,000} \right) \]

The formula to calculate the time the regulator will be on is:

\[ \text{Time (minutes)} = \frac{\text{CO2 Needed (cu.ft.)}}{\text{Flow Rate (cu.ft./min)}} \]

1. Experts disagree about the optimum level of CO2 for plant growth. You can find arguments for 800ppm, 1,000ppm, 1,200ppm and 1,500ppm. We recommend starting at 1,000ppm, then adjusting your CO2 levels over time with experience. CO2 levels below 400ppm and above 1,500ppm will reduce plant growth.

2. Experts do agree that raising CO2 alone will not guarantee plant growth. Proper soil, nutrients, watering, light and cleanliness must be achieved in combination with enhanced CO2 levels for optimum results.

3. A fan inside the grow area pointed at the end of a length of tubing from the regulator will circulate the CO2 in the air for maximum benefit. Otherwise, you can connect the regulator to a length of tubing with pin-holes strung around the top of the grow room so that the CO2 will "drop" on the plants (CO2 is heavier than air).

4. If you are growing indoors, purchase an inexpensive timer to control your day/night light period. Never run CO2 during the dark period.

5. Note the temperature on the Indoor CO2 Grow Controller temperatures above 27°C (80°F) over time can result in elongated stems and lower yields of mature plants.

6. In natural conditions, CO2 levels range between 360-395 PPM. If you don’t keep CO2 levels topped up (either by ventilating with fresh air or supplementing with a CO2 cylinder or burner) your plants will run out of food, photosynthesis will slow, and plant growth will be lackluster.