My temps are 75f lights on and a low of 55f lights off. Are these temps ok? They seem to be doing well.
Ya, I've always tried to keep daytime and night time temps within 10 degrees of each other. I guess it would be similar to a more natural environment, but I always thought higher fluctuations in temp wouldnt be as beneficial to the plant. Find a good temp and try to keep around it
55 isn't bad, or at least not bad enough to spend the money heating the room at night. Below 50 could mess up your plants.
During flowering its not that bad. I would still try and keep the temperature fluctuation between 10-15 degrees or even lower as this will prevent any shock to your plant. Remember to keep your humidity levels lower during flowering than normal. Dont want any mold during this stage and its beneficial for your plants.
Your temps are fine don't let it drop below 55 though that would slow growth quite a bit. Also if you get over 85 degrees you could get some really airy heat stressed buds