I’ve got both a rockwool slab system and a horticultural clay system. They both use a drip. The pebbles are watered hourly and the rockwool is watered twice every day. During the dark period, do I have to water the marijuana plants? Do they take up nutrients only when the lights are actually on?
A once-daily watering during the dark period allows the roots to have some freshwater to draw upon. This water is used to promote growth while also rinsing surplus nutrients from the medium.
Marijuana plants don’t simply “turn off” at night. Photosynthesis stops because of the lack of light, but other metabolic processes must still continue (i.e. respiration, tissue building, etc.). The cells are powered by the sugars that were created earlier in the light period. Tissue is built when plants combine nitrogen with sugar to produce amino acids (otherwise known as protein’s building blocks).