On to week 2!

Day 7 has come and gone. Excited about my first weeks growth! Just changed the water.. PH’d at 5.7 with 250 PPM. Anybody have experience with water farm hydro set up? My set up is in the garage. I have a heater in the garage I can use but Im wondering when I should cut it on.. what temp is too cold? I’m in the south.. so it doesn’t get very cold. Just curious on y'all's thoughts.

Thank you!
RH.