With the grounding screw you will prevent the steel fittings of your pool from rusting due to any electrical shunt produced by a salt chlorinator, etc.
https://www.piscinayspa.com/se/pool-accessories/11/saline-chlorinators/9324/eddy-current-kit/FS9324Kit de corrientes parásitashttps://www.piscinayspa.com/fotos/productos/kit-de-corrientes-parasitas.jpeg56.0056.00InStockZodiacSwimming Pool Accessories/Saline chlorinators/Zodiac Saline chlorinator5