Chapter 2 - Measuring Airborne CO2

Chapter 2

Measuring Airborne CO₂

CO₂ is calculated and measured in parts per million - ppm . Country air contains about 300 ppm. City air usually contains about 400 ppm. Most researchers put the ideal level for maximum growth rate at about 1500 ppm, or five times the amount of CO₂ found in fresh air.

Inexpensive CO₂ Tester

The simple inexpensive test kit pictured here is available

from a number of garden supply distributors across the country.

Each glass tube is good for just one test, and costs about $7.50.

This is a small price to pay for the benefits that come from proper

CO₂ enhancement, no matter what size the garden.

Using the CO₂ Test Kit

1.	Place the short piece of flexible plastic tubing on the end of the

plastic syringe.

2.	Carefully snap off each end of the glass tube.

3.	Push the plunger on the syringe all the way in to clear any

air.

4.	Draw back the plunger to the 100 cc mark in the air to be

tested.

5.	Place the glass tube in the open end of the flexible tubing.

6.	Push firmly on the plastic plunger and slowly force the air

through the glass tube. The entire process should take about

one minute.

7.

Notice the white powder in the tube change color (either red

or blue depending on the brand).

8.

When all the air in the syringe has been forced through the

glass tube, the CO₂ level is indicated by the top of the colored
band in the indicator tube.