wondering about humidity

well since where i am at its starting to go into fall, cooler nights. i grow indoors, my house temp usually doesnt drop below 70. but in my grow room my humidity gets up to prolly 60% or so at night when my lights and fans are shutdown. so i was wondering should i be worried about it getting that high at night, usually drops down to 40% or so give or take a few. so i was thinking if its a bad thing maybe leave my one fan running to keep the air moving? was just curious if maybe i should keep lower even at night? thanks for all the advice i have been getting. actually what would be a good humidity to maintain?

I try to maintain 60-70% in veg and 30-40% during flowering. I let my circulation fan run 24/7. It doesn't use much energy and it is quiet.

cool, guess i will set up my fans so one stays one. thanks for the info.