I have 4, 26 watt CFL's running in a rubbermaid box about 3 feet tall by about 18 inches deep and 16 inches wide. Its hosting 3 day old sprouts...I'm keeping my thermometer on the edge of a pot right now to measure what the temp. is at the sprout. Bubs about 4-5 inches from the sprouts. The temp hovers around 90-94 which is obviously not good. However if I hold my hand even an inch from the bulb i feel almost no heat. I have an exhaust fan and im installing an intake fan tomorrow. Basically I confused where that high temp. is coming from. The exhaust feels cool, the bulbs seem cool from the sprouts view point, when I open the box its not like I feels 90 degrees in there. The temp outside the box is probably about mid 70's. Are my plants hating this? And whats with my box heat soaring?!
it's the lights, you need ventilation pronto. not only for the heat, but plants need air (specifically co2)! you run a high risk of sending them into shock with high temps. could also be your thermometer but i doubt it.
I'm hoping the 90mm intake fan is going to do the job. I can leave the front lid cracked through most the veg. period but eventually it will have to stay on so im trying to solve the issue now. I'll search on CO2.
Yeah im going to switch my current exhaust fan with the one I was going to use as a intake. Its a little bigger and while the specs dont tell me its CFM im pretty sure its going to pull more. I checked out CO2 looks like you have to spend at least 300 to get a good system. Im thinking of hiring 6-7 immigrants to huddle around it and breathe on it.
LOL neat. Don't worry about a CO2 system man, the co2 just in the air will be enough. The only time you'd need to worry about adding a co2 system would be if you had everything else to match it (proper lights etc.). It goes like this, your plant is only gonna grow as big as your weakest link allows. So you could add co2 all day long and it wouldn't make much of difference without enough light to go with it and everything else. it's true that co2 can add some explosive growth and buds, but they don't survive on that alone, if that makes sense
Yeah I understand the weak link thing. I sell music recording equipment where people will buy a 600 dollar microphone and attach it to a 100 dollar preamp. Blows my mind everytime. This is my first grow so im focusing more on nutrients, airflow, temp. before anything else. I appreciate all the help!
my cfls raise the temps 7 degrees *C* in a 5'x6'x18" box with fans on! cfls get hot, usually....just not *as* hot as hid. heat rises so i would personally mount your exhaust right on the top above your lights.
it's exactly the same concept. i dabble a bit in the music industry too so i know what you mean i concur
Wow that box brings back memories. I used 2 of those together once. I cut a hole in the top and stuck a small 5 x 5 fan in the small hole and put another in the actual cab I built. Come second and third grow I just used one in the box and used the other in a box that I kept clones and a mother inside. Hot days were a bitch, it got real warm real fast. If you have central air and don't let it get above 80 inside you should be all set. If you are worried you can get a digital outdoor thermometer for like 5 or 6 bucks and put it in the box.
Haha yeah its hard to beat a 11 dollar huge ass box. Though I saw a thread on here with a box from home depot thats bigger and has two opening doors. Im going to pick that up next week and rig it up better then transfer everything. Im going to do SCROG and no more than 2 plants in it. Good news just installed the bigger exhaust fan and moved my old exhaust fan into a intake position. temps. down hovering around 85 now!!! That might be as good as i can get it for now. Luckily its a basement in the midwest so shortly it will be getting down in the low 70's in here.