VPD Questions

Hi all,

Just got my Pulse Pro a little over a week ago and I am addicted to the data! Speaking of which - I just did an overhaul of my grow tent (larger exhaust fan, moving exhaust inside the tent, moving fans around, CO2 generator bottle in tent) and had some questions about VPD and my ideal climate.

I’m growing a Forgotten Cookies autoflower by Mephisto Genetics and currently at day 38 and in flower. My current VPD setting is from the generic flower template (target is 1.5). With the new exhaust I’ve been able to get temps down so I can lower my RH to get to my target, but I was wondering how good of a baseline target that is? I’ve heard a lot that I should have RH about 50% or lower in flower and want to base my tent climate off of that.

I guess I wanted to know what people set their VPD to for autoflowers in flower? Just looking for a little insight so I can really dial in the environment. Any and all advice greatly appreciated :pray:

Can you share your current environment? That way you can get some better feedback

Temperature and humidity is set different when running CO2 with higher temps you can safely run RH at 60-65%, just make sure you have good air at top and bottom of canopy. There’s VPD charts available online. There’s a chart that you can down load on the main Pulse One website.

What type of lights are you running? Conventional thinking is to get your temperature right then adjust humidity from their to get vpd to where you want for the stage of the plants life. Pulses vpd article has some good info if you haven’t read it yet. I agree with Gemann you can run Temps and humidity higher with co2. I’ve grown quite a few mephisto autos but not that one. Every strain I’ve grown from them can take a beating but I’d try and get those Temps up. 75 is optimal with hid and 80 to 85 for led. To really dial it in you need an ir thermometer to get your leaf surface temp dialed in.