![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
And the way it works is that there's a pump at the bottom, which 12) ________sends some of this liquid nutrient solution up to the top, which then trickles down through plants' root systems that are suspended in clay pellets -- so there's no dirt involved.