For balcony growers, compact coil pots use a small copper helix inserted into the medium

https://www.scribd.com/document/1024346197/Backyard-Experiments-Measuring-ElectroCulture-Results-at-Home-231706

For balcony growers, compact coil pots use a small copper helix inserted into the medium, aiming to localize subtle charges near roots without requiring tall poles or complex grounding arrangements.