Questions about Setup and Environment

I had bud rot for 2 or 3 years almost in every grow. Since i move air a lot inside and have good air change from and into tent - have 0 bud rot for last 6 years indoors. Sometimes in late flower during night, especially first night after watering i have spikes up to 70% rh and still all good. 55-65 is my average and i have no problem in UK. Lower temps in flower wont let plant to strech out, otherwise penetration of light looses potency deeper into canopy, so chubby plants are better. Plus high temps in flower makes bud itself more airy and not dense, 20 could be too low tho, i would have 22-24 during day, 19-20 for nights. If control is possible ;))) Distance is very specific, i blast a lot, mine never bigger than 30-40 cm from top of canopy. People count dli, i work more with simple lux app to get to know light, but generally from many tested - none needed diming or higher height with established or flowering plants. Tested not one model of Mars Hydro, plus bought few leds by my own.