Okay, I thought you had the string tied around the stem- just trying to eliminate possible stressors, lol!
You're running on the cool side you know... you can actually bump your temps up to the high 70s and the plants will be delighted.
Keep checking to see when the pots feel 'light' and need to be watered, give it another day or two,and see if they perk up. They may be using water faster because your ventilation is stripping out the moist air, and I suspect the low temps are also contributing to the general dolorous air they have