VDP and Co2?

I was told to run my temps higher running c02 and having powerful led lights… I bought the pulse with c02 to dial this in with vdp cause I couldn’t find any charts explaining it. Anyone care to help me understand. I’m currently running my temps at 78 to 80 with 50 to 55 humidity cause I’m in my 5 week of flower

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I am excited to see what the experts say in response to your inquiry, and in the mean time I wouldn’t mind sharing my novice understanding.

There is a chart that Peet posted earlier which demonstrates the first piece of my understanding, ideal growth rates vary by several variables, and temp is one of them. Temps around 75 F ish I believe are ideal.

However, when you supplement co2 up to 1500 the ideal temp raises up to between 80 -85, I would assume closer to 85 if I recall is a sweet spot for optimizing growth rate.

Then the VPD calculation, the sweet spot for humidity based on vapor pressure deficit will vary based on temps and if you hit temps of 85 for example, your going to want you humidity up around 80%.

80% RH during bloom though: that creates additional issues, and is thus discouraged by many. It can create a thriving environment for various pests, including aphids, it can trigger mold growth and powdery mildew, etc… so, unless you feel equipped to handle these sorts of issues preventatively, you have to find your own balance.

The pulse monitor will give you a sense about the ideal RH for a given temp, or vice versa, and thus show you how to calibrate your humidistat for example based on the temps your system is running.

In my personal experience, my garden was not dialed in and prepared to handle the additional issues, but in my pure enthusiasm I had to try and see what would happen, I let my temps hit 85 avg, let the humidity hit 80… and I noticed a couple of things:

I knew I had an aphid problem which I believed at the time I had gotten under control: I discovered I was wrong and they became more prevalent.

I also always knew I needed to panda paper the exposed wood including some walls and the roofs, but I was waiting on the panda paper in the mail at the time.

So I noticed mold starting to grow everywhere, starting to form on various parts of the walls, ( I immediately bleach treated it when I saw it ), It started to grow on the surface of the plants soil ( I just scraped it off and ordered some biological fungicide ( organic ))… and… well, the plants…

They took off, literally growing 1.5" in a day… they also, though, exhausted their supply of nutrients quickly, on that same day they showed signs of nitrogen deficiency.

This correlated with a bunch of other tough lessons: learning about daily light integral by frying several plants, learning about the failure of certain soils I had to drain enough to accomodate automatic watering cycles ( resulting in root rot )… so, I have had a rough couple of weeks to say the least…

But the one thing I will never forget: hitting 80% RH and 85 F with 1500 ppm Co2 definitely seems to have been a profound sweet spot… and for the curious types like myself I had to experience it for myself.

Hope that helps fill in the gaps and I am excited to see what the others say and share.