24/0 is a schedule with continuous light and no dark period. Photoperiod cannabis stays vegetative under it, because long uninterrupted darkness is what triggers flowering. It is used in veg and for clones, and by some growers for autoflowers.
In practice
24/0 gives the highest DLI for a given PPFD: 400 µmol/m²/s on 24/0 delivers about 35 mol/m²/day, the same as 540 µmol/m²/s on 18/6. That lets growers run a fixture dimmer, closer and more evenly for the same daily light, which can suit seedlings and clones.
Costs: higher electricity use and no cool night to drop room temperature or humidity. Watch for interveinal leaf mottling or chlorosis in some cultivars under continuous light, a response documented in several other cropsbeing reviewed. If a cultivar shows it, switch to 20/4 or 18/6.
Don't confuse with
- 18/6: the conventional veg schedule.
- 24/0 in flower: photoperiod plants will not flower under it; autoflowers will, but results vary.
Myth check
GenetixBay house position: 24/0 in veg is endorsed. Cannabis does not need a "sleep period" in veg. The claim that plants must have darkness every day to grow well is a Myth for vegetative cannabis. Grower experience is broad (Grower practice); controlled cannabis data are limited, and members are welcome to run a Mythbusters trial of 24/0 vs 18/6 on their own cultivars.
