Gear talk - VPD

[Rocket Soul]

What are people using to measure VPD?
Temp/rh meter and the chart? Or even VPDchart.com?

Or do you use a device that just cuts out all the fuzz of first checking the hygro and then consulting a chart?

I know theres a few devices around
- Pulse has a standalone device, fairly expensive iirc about 200.
- the AC infinity controller - not seen it in action properly but looks real nice. But i cant really see it as a standalone device.
- Trollmaster has a unit but again its something not quite standalone (and not cheap) its part of their device ecosystem.

Am i missing some device on the market? Seems like this is a niche of the market completely uncovered: why cant i just have a hygro thermo/rh meter that just gives me the vpd at the same time, and not have to pay a fortune???

I wanted to ask everybody what their thoughts are on this, what it would be worth having something like this cause i might have an idea of how to get to it.

 

[DCcan]

I'm using the AC infinity controller, price isn't too bad for the other functions it has.
Turning off lights and pump costs extra for gizmos, buts its a good deal as part of a new exhaust duct with the fan.

 

[Rocket Soul]

I agree, if youre already in the ac environment its great value but you wont be able to use it in another place: say you wanna check on your veg space which is on a standard extraction fan, you cant bring your ac over to measure real quick.

 

[DCcan]

Doesn't AC Infin have a handheld device? I think I own one!
You just have to let it acclimate for a few minutes in the area you test for humidity to stabilize.
Some people just stick it in and pull the trigger, user error.

AC Infinity VPD Thermometer, Handheld Environmental Monitor, Captures Leaf VPD and Temperature, Calibrates Smart Controllers, Precision Infrared Range for Plants, Grow Tents, Greenhouses, Terrariums : Amazon.co.uk: Garden

AC Infinity VPD Thermometer, Handheld Environmental Monitor, Captures Leaf VPD and Temperature, Calibrates Smart Controllers, Precision Infrared Range for Plants, Grow Tents, Greenhouses, Terrariums : Amazon.co.uk: Garden

www.amazon.co.uk

 

[Rocket Soul]

Doesn't AC Infin have a handheld device? I think I own one!
You just have to let it acclimate for a few minutes in the area you test for humidity to stabilize.
Some people just stick it in and pull the trigger, user error.

AC Infinity VPD Thermometer, Handheld Environmental Monitor, Captures Leaf VPD and Temperature, Calibrates Smart Controllers, Precision Infrared Range for Plants, Grow Tents, Greenhouses, Terrariums : Amazon.co.uk: Garden

AC Infinity VPD Thermometer, Handheld Environmental Monitor, Captures Leaf VPD and Temperature, Calibrates Smart Controllers, Precision Infrared Range for Plants, Grow Tents, Greenhouses, Terrariums : Amazon.co.uk: Garden

www.amazon.co.uk

Thats a great looking thing. I feel vindicated but cheated: i had a sensor scoped out for a few years, very nice spec and scando made, with logging and even air pressure and bluetooth. But i didnt have anyway to code up an app that would do the calculations in your mobile. Im getting claude code next month, im going to grabb his balls and squeeze until he makes me the exact website i want for my day job, and i thought hey, made i can do that thing i thought of with claude. But this device makes it a bit superfluous.

 

[DCcan]

Thats a great looking thing. I feel vindicated but cheated: i had a sensor scoped out for a few years, very nice spec and scando made, with logging and even air pressure and bluetooth. But i didnt have anyway to code up an app that would do the calculations in your mobile. Im getting claude code next month, im going to grabb his balls and squeeze until he makes me the exact website i want for my day job, and i thought hey, made i can do that thing i thought of with claude. But this device makes it a bit superfluous.

It even does the air VPD and the leaf offset VPD calculations.

 

[Rocket Soul]

It even does the air VPD and the leaf offset VPD calculations.

Its pretty much exactly the kind of gadget i was after.
My sensor would have a couple advantages: data logging, and air pressure compensation: vpd works out different in elevation and around storms and such which alters the air pressure drastically. I dont think its a project i will pursue, maybe just for the kicks of trying something out

 

[RickM]

I just have a temp\rh digital thermometer in a couple places in my grow room. I have a couple charts posted in there, 1 for veg - 1 for flower. I'll adjust my exhaust flow depending on the humidity and heat. I don't maintain a "perfect" environment, but I maintain it within the vpd chart ranges for the most part.. sometimes warmer, sometimes cooler. In the winter a run a vent off my furnace. My grow is in my basement. For leaf temps I'll subtract 3-5 degrees off my ambient room temp.

 

[Rocket Soul]

I just have a temp\rh digital thermometer in a couple places in my grow room. I have a couple charts posted in there, 1 for veg - 1 for flower. I'll adjust my exhaust flow depending on the humidity and heat. I don't maintain a "perfect" environment, but I maintain it within the vpd chart ranges for the most part.. sometimes warmer, sometimes cooler. In the winter a run a vent off my furnace. My grow is in my basement. For leaf temps I'll subtract 3-5 degrees off my ambient room temp.

My take on vpd is that its not a goal in itself, its just a nr. The real deal is plant expression: what does your plant look like? Slouchy and sloppy with hanging leaves or leaves stretched out, prayer style? If theyre looking good then F vpd, theyre happy. But if you see sloppy leaves consult vpd in order to get an idea of how to move your climate, adjust until you see the plants are thriving.
In the test grow with my buddy he had a new location setup with a bigger tent. Environment was a lot drier and vpd was hard to get right for veg in high intensity. But vpd is only one of the factors in plant transpiration: blue and uv spectrum, CO2 light intensity, especially in the "blurple" part of the spectrum all plays in. Green inhibits transpiration which is also a factor. This is the girls going into the new space from a plain white fairly green heavy spectrum.

New light has a bunch of blue and target uva. Over night after having adapt to the new light, same environment:

Its maybe subtle (remember it different from the foto) but quite clear: stretched out leaves and generally more happy looking plants. If you can get there then you wont have to worry about vpd, only that you have decent temps cause metabolism always needs to keep up with light intensity.

 

[Milky Weed]

yea I got the handheld temp gun, and lucked out with an ac infinity controller that came with a fan and the 4x8. Haven't looked at it much, but it does track humidity and temp. Would be cool if it has a vpd setting no idea how old it is

 

[RickM]

My take on vpd is that its not a goal in itself, its just a nr. The real deal is plant expression: what does your plant look like? Slouchy and sloppy with hanging leaves or leaves stretched out, prayer style? If theyre looking good then F vpd, theyre happy. But if you see sloppy leaves consult vpd in order to get an idea of how to move your climate, adjust until you see the plants are thriving.
In the test grow with my buddy he had a new location setup with a bigger tent. Environment was a lot drier and vpd was hard to get right for veg in high intensity. But vpd is only one of the factors in plant transpiration: blue and uv spectrum, CO2 light intensity, especially in the "blurple" part of the spectrum all plays in. Green inhibits transpiration which is also a factor. This is the girls going into the new space from a plain white fairly green heavy spectrum.
View attachment 16746
New light has a bunch of blue and target uva. Over night after having adapt to the new light, same environment:
View attachment 16749

Its maybe subtle (remember it different from the foto) but quite clear: stretched out leaves and generally more happy looking plants. If you can get there then you wont have to worry about vpd, only that you have decent temps cause metabolism always needs to keep up with light intensity.

Nice looking plants!

 

[Rocket Soul]

Nice looking plants!

Thanks Its the first run with these lights, at my buddies. Check it out over at my led thread