What's the optimal temp In a grow room

Hi there.. the temperatures you mention are fine. if it's going above 30 you'd be better off adding some co2, but what you state is in a good range still.. Humidity is another question though. If you're in the veg-phase you'd preferably want to be higher than that (while for the blooming phase you'd be good). I suggest googling a vpd chart, that provides you information about the ideal humidity at a given temperature for a specific phase of the plants lifecycle, as this has to do with how much water they need to evaporate. I personally try to follow the chart mentioned here (full link so you can read up a bit more on the topic): http://www.just4growers.com/stream/temperature-humidity-and-c02/vapor-pressure-deficit-the-hidden-force-on-your-plants.aspx happy growing!