Understanding VPD and more info

[mrfreeze682]

so i came across this info and it really piqued my interest.... its the basics for vpd i surmise VPD INFO

 

[PahPahCee]

Here’s a neat chart; https://vpdchart.com/

Just be careful. Sometimes chasing the vpd chart can cause it’s own issues. In example, taking it above 70% humidity in my experience caused the plants stress.

 

[mrfreeze682]

cool. Im just researching right now. Gona start building my mext setup and want to include vpd Maybe.... i wana get into ponic phonic land but people get lost in those woods its scary... lol

 

[stevec217]

Here’s a neat chart; https://vpdchart.com/

Just be careful. Sometimes chasing the vpd chart can cause it’s own issues. In example, taking it above 70% humidity in my experience caused the plants stress.

In your experience, does it make sense to stay on the upper limits of vpd to decrease humidity? For example... seedlings require .06-1.0kpa. At .08 in my setup the humidity is around 74% during the day with alot of airflow. At 1.0 I can maintain 68% humidity. I'm very new to this, lots of questions to be answered. Thanks!

 

[PahPahCee]

In your experience, does it make sense to stay on the upper limits of vpd to decrease humidity? For example... seedlings require .06-1.0kpa. At .08 in my setup the humidity is around 74% during the day with alot of airflow. At 1.0 I can maintain 68% humidity. I'm very new to this, lots of questions to be answered. Thanks!

I would target the lower humidity. You can get away with high humidity in veg. When you start to flower you may want to bring the humidity down. I like to keep it down around 60% in late flower. This is where vpd chasing it’s hard because 70% puts you at a higher risk of budrot.

under LED we want to target a leaf surface temp of around 80-84F.

 

[stevec217]

cool. Im just researching right now. Gona start building my mext setup and want to include vpd Maybe....

By the time we get to flower, the humidity and temp will be much more manageable. I haven't tested leaf temp yet, one of the tools I haven't picked up yet but on the list

 

[stevec217]

I would target the lower humidity. You can get away with high humidity in veg. When you start to flower you may want to bring the humidity down. I like to keep it down around 60% in late flower. This is where vpd chasing it’s hard because 70% puts you at a higher risk of budrot.

under LED we want to target a leaf surface temp of around 80-84F.

By the time we get to flower, the humidity and temp will be much more manageable. I haven't tested leaf temp yet, one of the tools I haven't picked up yet but on the list