can ranging temperatures cause bad things to happen

Im growin some nl#5 and my grow box varies with it closed and the fan on and whatnot it runs at about 90 degrees but when i open to bask in its glory it gets down to sometimes 70 but only sometimes usually like 78-80 ish range. google didnt help so info would be appreciated thanks in advance.

yup...plants get too stressed and become hermi

You want to be around 70-80 and have only about ten degree variations from day to night cycle. Hotter temps lead to slowed growth, increased bugs, and general plant stress, it can even lead to nutrient problems. One thing I notice is that when the temps are high, new leaves are much skinnier, to decrease surface area for water loss, which means the plant absorbs much less light and this is a big hit to early yield.
The thing to keep in mind is that the less ideal the conditions, the smaller the final yield. It is mostly a matter of optimizing, since the plants are quite hearty and will survive a lot. Hope this helps!

yes that did mchelp and shit well i havnt seen any signs of going herm and im 7 weeks in flowering but how can i make more constant? 250 w regular ass pos light bright though, and 1-42 w cfl and 2-23 w cfls

To regulate temps you definitely need airflow. It isn't too hard to put some fans around that exchange the air in the grow room/box with air in the rest of the house so long as you don't have to hide it. I went cheap and bought a cheap $30 cpu power supply and stuck a few large computer fans in that flexible duct stuff (flexible shiny stuff not aluminum) and two of those in-line fans bring air in from the house and directly between the plants and lights. Cost like 50 bucks total. You can get another couple fans and a duct and pull air out of the room too, or go some other route.