Rockwool vs Grow Sponges for Countertop Hydro: I Compared Every Option So You Don't Have To
I was paying $3 - 5 per OEM pod until I found sponge replacements for $0.15 and rockwool for $0.03. Full cost breakdown for AeroGarden, iDOO, and LetPot owners, with the quality warning nobody else mentions.