at night my humidity is going up to 70. but if i use a dehumidifier it stays at about 40/50 but the temp is then hotter that the day time temp. day 75 night 80. will this affect the plants in any way. i read heat makes your buds run does this count at night.

I don't remember heat making buds run ? You want to be concerned about rez temps more. It is suggested to keep humidity to 40% or less because you don't want mould to grow. I find the less humidity the bigger my trichomes are.