Pham i think there to stop particals from getting into the sprayer look: (its the 3 one down) i thought it was kinda pointless too but i think they gotta give them to you for a reason

GENERAL HYDROPONICS


also i let them get sprayed for the last 8 hours and no luck the rocks seem to be drying, i can only think when i have a hps on it will dry 1 a split second