You would be surprised how sudden and agressive they start guzzling around day 20 of 12/12. Say I am watering once daily on day 19. Day 20 they are dry as a bone if I wait too long, they need water at more like 16 - 18 hour interval now. I noticed with coco it goes from halfway dry to really dry in short order. A moisture meter reads top green at 2pm, then at 5pm it's middle green but on 30 more minutes it's going red. So the perfect time to water is when the moisture meter says middle green or just above. That is optimal IMO, but treating all the plants the same with auto watering just doesn't work if they are drinking at different rates. You can error on the side of over watering to a degree but you can't keep them saturated constantly. So if you have a plant that needs it's water every 36 hours, you might get away with watering it early but maybe not 12 hours early... doing that constantly ends up causing root rot. Seen it. Looked at the roots.