VPD: what's the minimum temperature I should ...

@m0use; vp should have been vpd, was a typo. The environment is hard to maintain, so I'm trying to go with changing temp when can, and humidity when while targeting a good VPD Vapor Pressure Deficit ? I'm still trying to learn and understand the concept, so asking questions. But, I think its a way to look at temp and humidity as a single net result where you try to make it easier for the plant to respirate well for its growth stage. Anyways, thanks for the feedback. So far it sounds like ... I'll should the lights down to 12 and try to keep the temp over 20c/68f and try to bump humidity to go with it to get the lower vpd. as is , i think my temps are getting too low sometimes. ad humidity is a struggle. Anyways, at about 67f and 51% rh right now.