The intake into the cab is 6 inches and the intake to the lamp is 4 inches.
The exhaust for the lamp is 4 inches and the two exhaust for the cab are both 3 inches. I read where to use a smaller exhaust to create more velocity
and to create a force airflow to the exhaust. What about the thermometer location any idea if I am getting an accurate reading or is it just being run up buy the lamp. I to had my babies on cfl's and have transplanted to a larger pot and the hps.

Cactusman I love your location" from the basement of the alamo" that made my day.-peace