Is my root zone temperature too cold?

I have a few plants going under a 400W HPS in a tent. To cool it I have a vent to outside sucking cold air into the tent with a small inline fan. It works very well to cool the tent, but I just realized it is making my plants root zone very cold as they are in fabric pots and the cold air can pass right through. (Also I have the vent/ fan blowing underneath the canopies around the level of the pots). I have one plant in particular that I am worried about where the cold air is blowing directly on it. The buds - at canopy level - are at a perfect temperature with the lights on and this vent fan going. But when I feel the sides of the smart pot's they are in it is very cold right now. Idk the exact root temperature but I would guess as low as 50 farenheit or so. I think that's 10 celcius? Is this too cold for the root zone? Again the buds are at the perfect temperature, if not too hot (a few are fairly close to the light)

I'm thinking I might move this vent fan away and point it up or something so it's not blowing on all the fabric pots at the plants root zone. Then again, I want the airflow going underneath the canopy, and there's not exactly room for another fan atm lol... this thing is packed. So should I move it? Is this too cold for all the roots? The plants don't seem to have anything wrong, but it's getting colder out and I worry this fan could be making the roots too cold.

OK so I've got the root zone temperature at 14 Celcius which is 57.2 F. Is that too cold? The canopy temp is 75 F

Its ok, i grow outside in summer, some times temp go 0c degree.
Girls dont die
Now i have outside tent, there is -10.
Tent is 26c and root 17-18c...growing fine.
cold root=more oxygene...
I dont no where is limit for a roots...below 0

Honey Oil Riot Squad said:

OK so I've got the root zone temperature at 14 Celcius which is 57.2 F. Is that too cold? The canopy temp is 75 F

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Its not optimum. I would move it so its not blowing directly on the pots absolutely.

I moved it. it's facing a wall now so it doesn't help with air movement much, but still will cool it well. Better than right at the roots. Glad they are in no danger of dying!
I also stuck a timer on so it shuts off at night and doesn't make it too cold. (it's gettin cold out)

Thanks!

why are you pulling from outside? you can't use indoor air?....winter is coming and that will be a no no soon...well unless u live in say fl.

Honey Oil Riot Squad said:

OK so I've got the root zone temperature at 14 Celcius which is 57.2 F. Is that too cold? The canopy temp is 75 F

Click to expand...

I'm the same I try and use 15c as the minimum

use ur turkey (cooking) thermometer for accurate measurements

better to suck passive air in from the house low down

and vent out top most of ur grow space to outside

warning tho raising the temp does raise humidity

good luck

You could get a little steamer/vaporizer to raise humidity and temp. If the humidity is too high maybe a small heater fan on a timer that will do 10 or 15 increments.

"I'm thinking I might move this vent fan away and point it up or something so it's not blowing on all the fabric pots at the plants root zone"

...low end Siberians are known to install a incandescent bulb into a pet food tin

and attach that to ur inlet hose ..lol

good luck

Try this... if you exhaust outside and have an intake from outside then... put the two outside ports close together. I do this...my exhaust port is directly above my intake port by about 6". As the intake sucks in cold fresh air (which will often get down to -20c) it also sucks in a bit of the exhaust air which warms it up enough to keep the duct lines from dripping condensation and to not blast the girls with sub zero wind chills...lol

Also... my fresh air intake is at the top of my tent and i exhaust out the bottom. So the cold air warms up more when it enters the tent around the level of the lights. Keeps the lights cooler... and the roots done get chilled....

Sounds as if a fan speed controller might also help.
I don't think you mentioned the size of your tent or inlet and outlets fans.
Obviously we all would love optimum temps but i have successfully grown in a badly
Insulated area for years in winter with 600w HPS.
I lined my pots with polystyrene roll lol.. probably no good for airpots though.

Can do a lot of tricks with cardboard and tape. Can direct the cold air straight up. If you wanted

IceMake said:

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You dog.... LOL