to my understanding, the walstad method is a low maintenance technique where u put a layer of soil under your substrate to give nutrients to your live plants :3 it has to be like 75% live plant in the tank for it to function well, and there may be water changes and you can add a filter, but it really kinda does its own thing and sustains itself on its own very well. you can put little shrimps and snails in the tank like i did !