A pot is a root environment

The material around the roots has to hold water and allow gas exchange. Both matter.

After irrigation, some pores drain and contain air. Others retain water. That balance depends on the substrate and the container. Even container height can change how the same mix behaves.

This is why someone else's watering calendar may be a poor fit for your grow. Pot size, plant size, medium and environment all belong in the decision. A small plant in a large container does not use water like a mature canopy.

Before adding something to a struggling root zone, look at drainage, moisture and the time between irrigations. Nutrients cannot make oxygen irrelevant.

Next step: keep a simple record of irrigation and how the container changes between waterings. Learn the behaviour of the medium you actually use.

Reviewed 8 October 2026