Is VPD important?

[The70’s]

then light. lots and lots of light. start with more than you think you want. but you can work in to that a bit.

Right now i have about 460watts for a 4x4 i bought them back a few years ago.

Samsung LED’s and two dimmable balists

 

[TorturedSoul]

the soil probes are useless.

The Bluelab soil/media pH tester appears to be a wholly different critter than the usual "3-in-1 Moisture/pH/IDFK Soil Probe" K-Mart Special $9.99 garbage. I've never used it (only times I've wondered about soil pH, I did the generally accepted dry sample + distilled water mix/test procedure; most county agricultural extension websites explain how). But I just looked at the product documentation on Bluelab's website... automatic temperature compensation, listed accuracy @ 77°F / 25°C of ±.1 pH and ±2°F, two-point 7.0 and 4.0 (or 10.0, but that's irrelevant for our application) calibration, glass-bulb probe (I don't know whether it's replaceable, or the entire unit is disposable), proper "it dries, it dies!" warnings, instructions to hydrate probe for a time in KCl storage solution prior to first use, explanation of how to correctly store unit between uses, an onscreen checkmark that disappears every 30 days to remind user to recalibrate (calibration should be checked at least once per week, IMHO), actual "how to correctly measure soil pH" instructions, including drying sample and weighing out a certain amount and using a certain amount of distilled water, warnings to store probe in KCl storage solution and to never store probe in distilled water, blah blah blah.

So it's probably a decent device, and should work okay IF prepped, used, maintained / cared for properly - and they charge enough for the thing that it's possible the users actually will .

 

[The70’s]

The Bluelab soil/media pH tester appears to be a wholly different critter than the usual "3-in-1 Moisture/pH/IDFK Soil Probe" K-Mart Special $9.99 garbage. I've never used it (only times I've wondered about soil pH, I did the generally accepted dry sample + distilled water mix/test procedure; most county agricultural extension websites explain how). But I just looked at the product documentation on Bluelab's website... automatic temperature compensation, listed accuracy @ 77°F / 25°C of ±.1 pH and ±2°F, two-point 7.0 and 4.0 (or 10.0, but that's irrelevant for our application) calibration, glass-bulb probe (I don't know whether it's replaceable, or the entire unit is disposable), proper "it dries, it dies!" warnings, instructions to hydrate probe for a time in KCl storage solution prior to first use, explanation of how to correctly store unit between uses, an onscreen checkmark that disappears every 30 days to remind user to recalibrate (calibration should be checked at least once per week, IMHO), actual "how to correctly measure soil pH" instructions, including drying sample and weighing out a certain amount and using a certain amount of distilled water, warnings to store probe in KCl storage solution and to never store probe in distilled water, blah blah blah.

So it's probably a decent device, and should work okay IF prepped, used, maintained / cared for properly - and they charge enough for the thing that it's possible the users actually will .

Whoa, i think that was a full review, i did some cleaning and calibrating and storage instructions, its nothing more than a reliable tool.

 

[cbdhemp808]

I've never heard of VPD (Vapor Pressure Deficit -or- Density), so thanks for bringing it up. Here's an article about it from Mars Hydro. I don't know if I could do anything about VPD, since I'm an outdoor greenhouse grower, but I appreciate learning about this aspect of growing cannabis. From the article...

The significance of knowing your VPD is that you can better understand your plant's health in relation to other standard grow room metrics. As long as you know the healthy range for VPD, you could adjust aspects like your watering schedule, ventilation, or average humidity to bring this score more in line with the ideal range.