Adding Humidity questions???

Smokenpassout said:

I have a cloud forge T3 now in a 3X3. My lung room usually runs high humidity 65 percent to 70 even. For some environment reason it has dropped to a natural 50-55. So I have added the humidifier set to 60 percent for seedlings. How much humidity is best for mature vegging down the line. I understand flowering to drop to 50 and even 35-40 in last weeks of flower.

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Delps8 said:

Rather than set RH, have you looked into VPD?

VPD is a combination of temperature and RH and it can be a very important factor in plant health.

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Smokenpassout said:

Just haven’t studied vpd yet. I will check it out. Always done well just keeping relative temp and humidity in line.

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Delps8 said:

This is a good source of info. VPD drives transpiration which drives water uptake which is how 90% of nutrients (by mass) are brought into a plant. About 50% of nutrient problems are a result of poor VPD (according to a couple of sources). The good news is that it's usually pretty easy to keep in range.

If you're using the AI controller or even a standard controller (I use their C69 super duper +), it's a no brainer.

Set the controller to keep VPD at 0.8 in seedling, 1.0 in veg, and 1.2 to 1.4 in flower. My temps are pretty predictable so the C69 controls the amount of mist coming from their Thermocloud humidifier. Works like a charm.

Reading the product description for the AI controller tells me that it will set VPD automatically and then control multiple devices to keep it in range. AI is the way to go (I've been a software engineer for 30+ years).

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Smokenpassout said:

I actually just upgraded to AI Controller. Mainly for the extra four ports, but I figured since it wasn’t much more than 69* why not. Been using on manual control, but considering using the AI. Either way I can read up on VPD and change it over to that. Thanks.

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