how do i mesure co2?

how do i mesure co2 in a grow room i want to start useing it but how do i mesure what i have already so this way i know how much to add

Normaly you would use a ppm meter. They are quite expensive but with that and a solenoid you can regulate it very well. A cheap diy way of measuring co2 is a little syringe kit you can buy. It sucks up air and gives you a reading. They come with 3 syringes so it's only a one shot thing not to monitor regularly. I'll see if I can find a link or two for ya in a bit.

http://www.hydrofarm.com/pb_detail.php?itemid=7108 Co2 test syringe kit

http://www.co2meter.com/ Cheap co2 meters.

http://www.process-controls.com/EEProcess/Alnor/compuflow_co2.html More expensive type


Hope this helps. +reps welcome

Go on I'll give ya some rep, that's the best deal I've seen.

Thank you thank you.