Ok I’ve skimmed this thread and seems most of this is based on “indoor growing”?
I’m running in a homemade greenhouse and even with exhaust fans, last summer I was hitting 100 degrees or more at times. I combated it with closely monitoring watering. And the end result was good.
But…. I’d love to do better. A lot better.
VPD seems to be a big part of it. What led me here is I planned on using misters to aid in cooling the greenhouse. Temp= X Misters come on and cool by evaporation. My exhaust fans export the added humidity based on concerns of rot or mildew. But I’m sort of gathering I don’t need to be as afraid of humidity if the VPD is in check?
I have a SensorPush brand sensor in my greenhouse right now, but did not have it in previous grows, I bought it to learn what’s going on in the greenhouse throughout the day. This sensor is what alerted me to VPD.
I’d like to ease into all this slowly so I actually learn it and willing to take very small gains in the interest of understanding, rather than going for the ultimate and not knowing why.
With this said…… can/will I gain good insight into adding misters for temp control …. With the benefit of learning how it will affect my VPD, with small risk to the current crop.
9 months of the year we have very low humidity and to keep my RH up in the grow room takes way too much RO water. When it’s -20C all winter and the RH outside is about 5% my room RH may only be 30% and that’s if my controller is no turning on my exhaust fan because it’s not warm or humid enough to trigger it.
To compensate I water more and feed less. For a long time I couldn’t figure out why I was getting toxic salts buildup half way through flower that always got worse no matter what. To prevent it I feed about half the ppm of hydro nutes in promix than I was and got much better results. With chronically low RH you get high transpiration and more nutrients get pulled up for the plant to process so over time, starting in early veg, the leaves get overloaded with stored salts to the point that they start to burn all over and not starting on the edges like classic nutrient burn.
The leaves get all thick and start turning brown/orange/yellow all over the surface and end up all crispy and withered. It finally progresses even into the tiny bud leaves by the time the plants are done.
I’m now transitioning to using organics like 3 types of manures and dry nutes like Gaia Green, kelp etc using ProMix HP as my base. Been a 3 grow process of dialing it in but I’m getting there. Burned the first ones with just organics so it can be done.
The only water I ever use is RO or distilled. Our tap water comes from a dugout on the property and is 400+ppm and pH 8+ most of the time. Some little change with how full it is. No runoff with the spring melt this year so it’s about 2ft lower than usual for this time of year.
Good test spot for my new 12ft tinny and trolling motor.
