Thanks, but even with that it can be tricky to maintain relatively steady temps. If without supplemental heat his lights are driving the temps from 66 to 77, then just bringing the night temps up to say 70, could bring the daytime temps up to 81. Alternately if his basement temps are reacting to his house heat system, then the lights might not be that much of an influence. Either way he has to factor in what's causing his current temp swing.
In my garage, it's not as easy as just programming minimal heat parameters. I have odd dynamics where it seems like the space hits tipping points -- it'll stay at a steady temp for most of the day and then slowly rise, and then by early evening hit that tipping point and start to build up unacceptable amounts of heat rather quickly. It's forced me to keep my grow cooler than optimal so that I have a buffer at the end of the day and I don't overheat. I hate using the AC in November, at least if we have a normal December the outside cold will allow me more options. Hopefully
@Lennut 's basement provides a more stable platform and he can find his supplemental needs and stick to a steady program.