Yes those are dark time cycle temps.I feed them every watering the recommended doses of pbp bloom and beastie bloomz.sugar daddy and magical a little less than recommended dose.If it is the temps and not the nutes could I get back those nights when the tempwas low by fixing the temp?
Yes there is purple in some parts of all of them.In a couple just the top 2-3 inches are pure royal purp,it's kinda lovely.I would show pics but one pic of a two week early bud is still not approved I guess? Also my leaves are trippn,I dont know if going purp these other colors come first or they need something bad.I'll try and post some pics today.
Night time temps. down to about 60 degrees F are tolerable. Mid 50's will cause slowed growth and repeated exposure to temps. 40 degrees F or lower may kill your plants. However some Indica strains are very resiliant to the cold as their origins are from high elevations where temps. are naturally colder. If you are growing on concrete, elevate the pots off the floor to prevent the root system from getting too cold.
Will temps. this low slow the plants growth? Yes, most likely it will. 80-85 degrees F is optimal.