Grow Room Pulse Labs Tester Group

[wwwillie]

Hey Now!
Wow you guys are really working this stuff about VPD. This is great.
Thought I would update with some pictures of my clone tent. I have been fighting off a very persistent mite infestation but even so the plants are growing well and the flowers are developing nicely. I think the Trifecta Crop Control is doin a good job ad between that and the strong plants that NFTG grows I can get a good harvest from this crew.
I do know that the Pulse Nano is responsible for a good bit of the success by allowing me to stay on top of the environment.

no lights in tent on. I love the rich green color.

Lights on.

Random shots.

 

[Mañ'O'Green]

@okPeet did a calibration change for me and now my hygrometers are in agreement. I will post some data in a day or two.

 

[wwwillie]

OK I now get to put this to work. I am participating in the Prizm lighting test of a CMH setup, it's really sweet but has the issues that HID has with temps and the tent is not in my controlled grow room either. What a perfect set-up to use the Pulse Nano to first tune up my environment and then monitor it. Way cool.

Here is my graph:

You can see I moved the unit around 9 am. It told me right away what I already knew but this told me just how much each needed to be tweaked. At 10 am I added a humidifier. Now I can let the temp be a bit high and I'll ramp up the Rh to match for a decent VPD number. Love it, love it, love it. Oughta call it Setup-EZ for as easy as it just made it to start dialing in the environment!!!

 

[Mañ'O'Green]

OK I now get to put this to work. I am participating in the Prizm lighting test of a CMH setup, it's really sweet but has the issues that HID has with temps and the tent is not in my controlled grow room either. What a perfect set-up to use the Pulse Nano to first tune up my environment and then monitor it. Way cool.

Here is my graph:
View attachment 874871

You can see I moved the unit around 9 am. It told me right away what I already knew but this told me just how much each needed to be tweaked. At 10 am I added a humidifier. Now I can let the temp be a bit high and I'll ramp up the Rh to match for a decent VPD number. Love it, love it, love it. Oughta call it Setup-EZ for as easy as it just made it to start dialing in the environment!!!

I don't know how to express the value of the visual information provided by these graphs. It is like I was living in the dark ages prior to this. It would be hard to do a grow now without it. Sure we had the snapshot information before but this just takes it to a new more meaningful place.

 

[okPeet]

Loving it. Seems like it's really proving to be valuable. Keep the good posts coming, and we'll keep making it better

 

[Simplicio]

Transpiration cools leaf surfaces, so the actual leaf temp is typically less than tent air temp. I've been curious about how much less. There are 5 cheap RH/temp meters placed around the tent near the canopy surface, along with Nano. An infrared gun thermometer was used to measure leaf temperatures. The 5 RH/Temp readings were averaged to get single values, and 4 IR thermometer readings were also averaged. For a total of 33 trials (9 measurements each trial), spread over 5 days, the leaf temp appears to be 7 F lower than the ambient air temp. I saw that many people were assuming 5 F in a few internet posts. The tent air is very well mixed with 4 fans in a 3 x 3. This has important implications for VPD calculation. The tent has averaged about 80 F air temp and 60% RH, yielding a VPD of around 1.4 kPa, which is outside the approximate recommended range of 0.4 to 1.2. If the 7 F cooler leaf temp is used instead, then the VPD is 1.1, within the recommended range.

Being able to set Nano's temp/RH values to match tent values would be very useful.

 

[wwwillie]

Good stuff man!
Kinda jives with my half assed poking around. Nothing rigorous like you, but I did see numbers that are very close to yours... Cool

 

[Mañ'O'Green]

Same here no rigorous testing. My laser thermal leaf temperatures are all over the place in about a 10°F range so if I picked 5 as an average that would bring my VPD very much in line with the suggestion. I think that tweaking the Nano to just get good numbers misses the point. To me it seems most useful to watch trends and obvious problems. I have strived to get Good VPD before this tool but now I can see the longer term effects of what I am doing. I am weaning off the humidifier as the foliage is becoming more dense. It is still a little dry but that will change rapidly now. Here is a snapshot of the past 24 hours and I like what I see:

 

[Mañ'O'Green]

Ps here is a picture of the garden yesterday:

 

[wwwillie]

Nice, nice, nice! Sweet clean and green!

Here’s my mess o’ green for a comparison. The mites are tough.

Dang alcohol and photography don't mix. Sorry for the fuzzy, didn't really notice how bad until I saw them on the page! Yikes...