Do these plants look healthy?
- Thread starter Dave hill
- Start date
Looks great to me, but let’s play the game.
what’s your grow media? what are you feeding them? have you switched from veg nutes to flower nutes?
what’s your grow media? what are you feeding them? have you switched from veg nutes to flower nutes?
- Thread starter
- #3
Are you using soil, or coco coir, deep water culture
- Thread starter
- #5
I’m using coco soil mate, since Iv put a dehumidifier in there the humidity is good at 30% but the temperature has risen to 34 degrees because the dehumidifier is giving out heat
True that, yes I gave up on running dehum for same reason. Maybe try dehuey in same room but not inside tent?
Just A Simple Guy
Well-Known Member
That's what I do. I run a compressor dehumidifier in the spare bedroom along with a 5,000 BTU window A/C. In the grow space (closet) I run a 4" inline that exhausts into the unfinished attic, thus pulling in the conditioned and dehumidified room air and I also run small peltier dehumidifier and ultrasonic humidifier on an Inkhet controller in the grow space. This setup keeps %RH with 3+/- of target.
Why is there a big shady spot in the middle of the tent?? That dont look good. I'd change that. Other than the shady spot everything looking great.
30% is low. Check out VPD chart for the sweet spot. @+30C your RH should be up around 80% and that's bad for molds. Suggest checking this VPD chart and cooling things off a bit more. Can turn off the de-humidifier.
Here's the VPD chart:
Great catch Bobrown14 on the VPD way out of whack…..
Just A Simple Guy
Well-Known Member
Here's the formula I use for VPD.
Enter the formula on the next line into spreadsheet cell A10 (copy and paste it).
=3.386*(EXP(17.863-9621/(A7+460))-((A6/100)*EXP(17.863-9621/(A5+460))))
You will type-in 3 values into 3 other cells:
One thing I notice with my LED and running it All Bright is leaf temperature is always 5F+ lower than canopy temperature. I just ran the calc and canopy temp is 77.2, leaf temp is 70.5 and %RH is 45 for a VPD of 1.12.
According to that chart it would be 1.63 but it assumes leaf temp is only 1F cooler than air temp.
Enter the formula on the next line into spreadsheet cell A10 (copy and paste it).
=3.386*(EXP(17.863-9621/(A7+460))-((A6/100)*EXP(17.863-9621/(A5+460))))
You will type-in 3 values into 3 other cells:
- Cell A5: The air temperature (A5 in the formula)
- Cell A6: The air %RH (A6 in the formula)
- Cell A7: The leaf temperature (A7 in the formula)
One thing I notice with my LED and running it All Bright is leaf temperature is always 5F+ lower than canopy temperature. I just ran the calc and canopy temp is 77.2, leaf temp is 70.5 and %RH is 45 for a VPD of 1.12.
According to that chart it would be 1.63 but it assumes leaf temp is only 1F cooler than air temp.
Plants have the ability to create a micro-climate at the leaf surface and another reason why fan leaves are important.
