What is best light for auto flowers metal halide , h.p.s ? Also light schedule 24 on,18 on 6 off or 12 on 12 off?
Both answers depend entirely on your specific cultivar and goals.
Many people run 18/6 throughout an auto’s lifecycle. MH is okay for vegetative growth while HPS can be used for both veg growth and flowering. MH is not ideal for flowering.