abzem said:

A wise man once told me "Speak to the VPD Lord, and you will have the answers." So, I've traveled a long way and need your help.

I've read threads and a boatload of write-ups online about VPD and I'm struggling to keep my leaf temp down and therefore cannot find my Goldilocks ;) @Aqua Man

I'm in week 3 of flower.

I'm growing Auto's in 3 Gal Fabric pots in Ocean Forest + 20% pearlite with Nature's Living Soil.
VIPARSPECTRA XS1500 Full spectrum LED 28 inches from canopy & the dimmer at 75% strength. Only getting 33,000lux/462ppfd. (so I don't think I'm frying them.)
Watering ph of 6.8/7 about every 2/3 days depending when the pot feels nice and light.
Plenty of airflow on and below the canopy + good ventilation.

I've tried every parameter from 75F/55%RH to 82F/65%RH and the leaf temp always stays the same as the ambient temp or even 1 or 2 degrees above making my VPD too high.

Any advice on how to lower my leaf temps??

Thank you!

Click to expand...

abzem said:

I've read threads and a boatload of write-ups online about VPD and I'm struggling to keep my leaf temp down and therefore cannot find my Goldilocks ;) @Aqua Man

I'm in week 3 of flower.

I'm growing Auto's in 3 Gal Fabric pots in Ocean Forest + 20% pearlite with Nature's Living Soil.
VIPARSPECTRA XS1500 Full spectrum LED 28 inches from canopy & the dimmer at 75% strength. Only getting 33,000lux/462ppfd. (so I don't think I'm frying them.)
Watering ph of 6.8/7 about every 2/3 days depending when the pot feels nice and light.
Plenty of airflow on and below the canopy + good ventilation.

I've tried every parameter from 75F/55%RH to 82F/65%RH and the leaf temp always stays the same as the ambient temp or even 1 or 2 degrees above making my VPD too high.

Any advice on how to lower my leaf temps??

Thank you!

Click to expand...

• It's not possible to do this without automated controls that control both temp & humidity.
• It's not possible to do this looking at individual readings.