You need to download a VPD app tent buddy is very user friendly and has a PPFD calculator and DLI calculator but best of all has a very easy to use VPD calculator, keep them in the parameters and it's good to go, higher RH in the 75 and 27C is ideal for is ideal for veg and im flower you want to slowly drop down to the 50's over the course of flowering...21c and 55rh is prime for flower