you're looking for like 75-80 with lights. the thing to remember though is lights off temp you should be around the same. temps dropping during lights off can lead to moisture build up, and then other problems, mold and fungus. also the lower temps can stress the plant, shooting up and dropping so much. cooler temps also brings in other pests.. you might want to work something out to bring it down a bit, common sense tells me that when those lights are off its dropping a good bit. not sure what to tell you, gotta find a way to get a bit more air out. thats not HORRIBLE but, a little cooler would be good.
Shack