Water uptake is almost at zero.

hotrodharley

hotrodharley

Well-Known Member
“Flowering temperature is ideally at 84 - 85 °F. This will help keep leaf temps at the Cannabis-ideal 88 degrees when using our LED grow lights. Vegetative temperatures can range from 75°-90°. However, ideal vegetative growth will occur at 85 °F and 60-70% humidity.”

www.blackdogled.com

Expert Cannabis Growing Tips

Flowering temperature is ideally at 84 - 85 °F. This will help keep leaf temps at the Cannabis-ideal 88 degrees when using our LED grow lights. Vegetative temperatures can range from 75°-90°. However, ideal vegetative growth will occur at 85 °F and 60-70% humidity. Oscillating fans are key for...
www.blackdogled.com www.blackdogled.com

I’m sure asswipe above knows far better. Leave it at 70 for all I care.
 
crimsonecho

crimsonecho

Well-Known Member
i dont want to get into this led temps debate but because its winter and its cold outside i run my grow room at 24-25°C lights on and my heaviest drinkers drink more than a gallon every 1,5-2 days.

pots are mulched and everything so most of that water is going through the plants. they are big plants with 60x60 canopy on each in 70L+ pots so a gallon every 1,5-2 days is ok for me.

and this water uptake gradually slows down as they move into maturity so it may be that. they may just be maturing and drinking less. so although a week without needing water is concerning, i agree with people saying it looks fine.
 
LeastExpectedGrower

LeastExpectedGrower

Well-Known Member
hotrodharley said:
Yes raise your temperature to at least 80. 85 is fine. But 70 is just not warm enough for LED
Click to expand...
Agree. My offset is 2f degrees...so that means when my tent is 83 the leaf surface temp is 81, as tested with an inkbird IR thermometer. As far as I know most modern quantum boards which have limited IR will give you a few degrees less for LST. Once I aimed at keeping my temps in the 77f (lights out) to 84f (lights on) and concentrated on keeping my VPD in the right ballpark my grows got better and my plants' drank more. I went from watering to dryness every 3-4 days down to having to water/feed every other day.
 
hotrodharley

hotrodharley

Well-Known Member
LeastExpectedGrower said:
Agree. My offset is 2f degrees...so that means when my tent is 83 the leaf surface temp is 81, as tested with an inkbird IR thermometer. As far as I know most modern quantum boards which have limited IR will give you a few degrees less for LST. Once I aimed at keeping my temps in the 77f (lights out) to 84f (lights on) and concentrated on keeping my VPD in the right ballpark my grows got better and my plants' drank more. I went from watering to dryness every 3-4 days down to having to water/feed every other day.
Click to expand...
Basically same experience here when I switched to LED. Temperatures we didn’t like with HID are necessary with LED. Bought a Fluke IR thermometer and got it dialed in and haven’t looked back. Will they live at 70? Sure. But they won’t thrive there.
 
LeastExpectedGrower

LeastExpectedGrower

Well-Known Member
hotrodharley said:
Basically same experience here when I switched to LED. Temperatures we didn’t like with HID are necessary with LED. Bought a Fluke IR thermometer and got it dialed in and haven’t looked back. Will they live at 70? Sure. But they won’t thrive there.
Click to expand...
Over consecutive grows I've spent time trying to narrow my variances...so less range between my lights-on highs and my lights off lows and then do my best to keep my lights on temps tight and lights out temps as tight as possible too. That plus trying to hit closest to ideal VPD has been helpful as well, though I will say that watering every 3-4 days made it possible for me to do things like go away for a weekend here and there.
 
hotrodharley

hotrodharley

Well-Known Member
LeastExpectedGrower said:
Over consecutive grows I've spent time trying to narrow my variances...so less range between my lights-on highs and my lights off lows and then do my best to keep my lights on temps tight and lights out temps as tight as possible too. That plus trying to hit closest to ideal VPD has been helpful as well, though I will say that watering every 3-4 days made it possible for me to do things like go away for a weekend here and there.
Click to expand...
I bought an Inkbird thermostat and a small desk heater. When lights go out it keeps it around 70 in there.
 
LeastExpectedGrower

LeastExpectedGrower

Well-Known Member
hotrodharley said:
I bought an Inkbird thermostat and a small desk heater. When lights go out it keeps it around 70 in there.
Click to expand...
Yeah, I have an Inkbird therm (one of their wifi ones) and my heater is a super small oil-filled 400w panel. I'm only working with about 92 cubic feet of space and it's been perfect. I have mine set higher. It kicks on at 79, but of course it takes a bit of time to heat so it bottoms out around 76 or 77 before warming back up. https://www.newair.com/products/ah-400

Though I'm assuming your temps are probably generally lower knowing where you live. The room I have my tent is our boiler room and it ranges from about 65-80 with the door closed...though right now I'm drying the stuff I chopped last weekend and with the door open that room is 57-60 (perfectly happy with that for drying). Part of that is that we haven't been seeing anywhere close to the amount of sub-zero temps or snow that we normally get in the winter. The ground's not even frozen here yet.
 
madvillian420

madvillian420

Well-Known Member
I wouldnt exactly throw black dog led onto any list of reputable sources lol. Id say 85 is a good maximum but I dont ever get there on purpose. I grow with quantum LEDs purely and prefer to stay around 80-82f.

Lumping all "LEDs" into the same boat isnt fair, a lot of literature on LEDs is referring to blurples with different spectrums and power levels/canopy spreads than the good stuff available now.

anywhere in the 70^ - 85f range and youre fine.

Increase the airflow near your dirt and dont water again until it feels fairly light, you probably overwatered and now the roots and soil are oversaturated.
 
hotrodharley

hotrodharley

Well-Known Member
madvillian420 said:
I wouldnt exactly throw black dog led onto any list of reputable sources lol. Id say 85 is a good maximum but I dont ever get there on purpose. I grow with quantum LEDs purely and prefer to stay around 80-82f.

Lumping all "LEDs" into the same boat isnt fair, a lot of literature on LEDs is referring to blurples with different spectrums and power levels/canopy spreads than the good stuff available now.

anywhere in the 70^ - 85f range and youre fine.

Increase the airflow near your dirt and dont water again until it feels fairly light, you probably overwatered and now the roots and soil are oversaturated.
Click to expand...
How about Utah State University and Bugbee? Any better source?

“The actual temperature is very cultivar-dependent, but the ambient air temperature with LED lighting runs generally about 10 degrees cooler than other systems, says Ryall. Under HPS, growers aim for a 75-degree air temperature, which puts the leaf surface temperature at about 85 to 88 degrees. Since LED lighting runs cooler, he’s seen the best results by raising the ambient air temperature by about 10 degrees. Ryall likes to see that number at about 82-85 degrees, which will make a lot of growers “fall out of their chair,” he says. It might actually mean bringing the temperature of the grow area up a little to the best range for the plant.”

““Once [the plants] get too cool, it affects transpiration, growth and morphology, nutrient uptake. It can even affect CO2 uptake,” says Ryall. When growers report to him that the plants are feeding less, it usually means that the room has gotten too cool. “It all has to do with keeping the leaf surface temperature the exact same on that plant under HPS as it is under LED, regulated for ambient air temperature.”
 
G

Grow Monster

Well-Known Member
To each their own respectfully. I've run 85°f and I can tell u for sure now running at 77° is 100% better. Better smell and taste in final product. I stay between 74-78°. 85° should be max. High temps can destroy trichs. Colder temps also bring out plant colors. Same reason u keep drying temps low is to preserve trichs.
 
You must log in or register to reply here.
Top