Place your hand right above the canopy. If it gets too hot for your hand, it's too hot for the plants.
The colder the air your putting on that bulb the closer you can get it. Good luck
Been doing that but have seen people getting as close as 8 inches and am wondering how they get that done, trying to bring down the heat though. Temps are at 86 F now, I know they'll be fine but not trying to have my buds be fluffy. Thinking i should put co2 into the mix now maybe?
I've tried cool tubes in the past on 1200w grows, but they were little better than a floor fan blowing directly up at the bulbs. Cool tubes get dirty, are a PIA to keep clean (if you don't want to reduce your light with dirty glass), and I prefer having a floor fan that also aerates the plants. You can use a cool tube if you wish, but they're not worth the money or hassle, IMO, for vertical growing.Get a cool tubes with Vortex 449cfm should do it and you are going able to put them at 4-6inches ...
Ricky Do you have a chart with par output comparisons? As lumens mean nothing to plant growth.
View attachment 2635230Some say, cooltube. This is an 8"cooltube. I have it a couple inches lower, not much!
I've tried cool tubes in the past on 1200w grows, but they were little better than a floor fan blowing directly up at the bulbs. Cool tubes get dirty, are a PIA to keep clean (if you don't want to reduce your light with dirty glass), and I prefer having a floor fan that also aerates the plants. You can use a cool tube if you wish, but they're not worth the money or hassle, IMO, for vertical growing.
prawn connary i `am an admirer of your drop bulb grows years ago from another board. it made have to try it, and it was some of my most productive grows. i was booted from the board and i never got to follow your stuff as much as i wanted. at the time you were just running single bulbs. i bet the 2 your running now has to improve on your end results. the thing i liked most about it was the temp drops. thanks for the info you have spread.