What should be the hottest that my growbox gets when the lights are on? Right now with good ventilation in my box I get 85 degrees right next to where my plant is. When the lights are off its down in the 70's. Are these good temps? I want to slow the speed of my intake fan because it is a little to loud. If I do that the temp will probably go up slightly. Whats the hottest it should get? Sorry I'm baked right now so I hope that made sense.
Keep max temps under 85F, above that and the plants start to have trouble uptaking CO2. You could go higher temps if you supplement CO2, but that is not an easy undertaking (usually you need a sealed cool tube on the bulb so that you don't have too much ventilation in the cab, otherwise you are just sucking out all the CO2 you are producing). Measure temps under the light at plant-top level, that is the temp the plants are experiencing. I knew a guy who was having temp issues and decided he would just move his thermometer to different parts of the grow space until he found a temp that fell within range -- sorry, that doesn't lower the temps that count!
