24 HOUR CONTINUOUS LIGHT FROM GERMINATION TO FLOWER. I HAVE ALWAYS RAN 24 vs 20/4.I have had 0 pests in 3 years or growing and I use my lights and 0 heaters. It’s a set up that works for me. I have ran 20/4 in the summer to reduce heat but I didn’t feel I had the same results. Any one growing auto should try at least once.