Humidity

Bob's Auto's said:

I use this chart...save it, it might come in handy some time
View attachment 1415120

Click to expand...

Vapor Pressure Deficit VPD Calculator - Dimlux Lighting - The Best Grow Lights

Vapor Pressure DeficitCalculator Calculate both Room VPD and Leaf VPD automatically Just enter the value below to generate the VPD values for your room and your plants. You’ll need to know the room’s temperature, relative humidity, and the plant’s temperature. We recommend calibrating your...

www.dimluxlighting.com

Death The Cultivator said:

Many don't know that to properly measure VPD you need an IR gun to read the leaf surface temperature. The leaf surface temperature creates a + or - offset that helps dial in parameters way better than just using ambient temperature.

Vapor Pressure Deficit VPD Calculator - Dimlux Lighting - The Best Grow Lights

Vapor Pressure DeficitCalculator Calculate both Room VPD and Leaf VPD automatically Just enter the value below to generate the VPD values for your room and your plants. You’ll need to know the room’s temperature, relative humidity, and the plant’s temperature. We recommend calibrating your...

www.dimluxlighting.com

Click to expand...

Delps8 said:

If you're able to grow at 30%, more power to you. Me? Not a chance I'd grow something at that level.

30% RH is about ½ the recommended RH. If you look at a VPD chart, a grower has to go to extra ordinary lengths to come even close to an acceptable value. Photosynthesis isn't the only issue. With humidity at that level, transpiration rates take off and that can cause nutrient issues due to the significantly increased water uptake.

If there's nothing the OP can do about it, well, that makes it easy - he's just got to suck it up. OTOH, why not stack the deck in his favor and create an environment where the plant can thrive rather than just survive?

My tuppence.

Click to expand...

Delps8 said:

If you're able to grow at 30%, more power to you. Me? Not a chance I'd grow something at that level.

30% RH is about ½ the recommended RH. If you look at a VPD chart, a grower has to go to extra ordinary lengths to come even close to an acceptable value. Photosynthesis isn't the only issue. With humidity at that level, transpiration rates take off and that can cause nutrient issues due to the significantly increased water uptake.

If there's nothing the OP can do about it, well, that makes it easy - he's just got to suck it up. OTOH, why not stack the deck in his favor and create an environment where the plant can thrive rather than just survive?

My tuppence.

Click to expand...