What advantages (or disadvantages) can I expect if I let my marijuana plants use up the entire nutrient-water supply in my wick system? I’ve read elsewhere that it’s important to keep the nutrient reservoir at consistent levels. But my marijuana plants tend to grow better if I allow the growing medium (half-perlite, half-vermiculite) absorb all the nutrients and dry out every three to four weeks. My main concern with this procedure is that the roots will extend in search of more water. When I add the nutrient solution, the growing medium becomes rather wet.
The wick system operates with a wick (generally with a piece of nylon cord) to pull water from a reservoir to the planting pot using capillary action (which is a lot like using a tissue or napkin to draw water). The wick automatically draws more moisture to the container as it’s used up by the marijuana plant or evaporated. Thus, the moisture level is constant. There are also plenty of air spaces, which are vital for the roots thrive.
A lot of plants perform better when the medium is allowed to dry out because these conditions simulate those in the plant’s natural environment. Even so, cannabis tends to thrive without this cycle. Be sure to keep an eye on the dry-out cycle so that the leaves don’t start to wilt. Other than that, there really is no danger, unless the nutrient-water solution becomes too concentrated. Because your marijuana plants do better with the dry-out cycle, you should probably keep doing it. Inexperienced cannabis growers will likely find it better to keep the water level at the suggested height so that the nutrient-water solution stays the same. Then you can drain the solution without needing to rinse.