Spa System Flush super-cleans the inside of your plumbing system-- the hidden pipes and hoses that are the heart of your spa or jetted bath. Removes oily residues and deposits quickly and easily, without a lot of effort. Dirty buildup inside the pipes of your spa or jetted whirlpool bath reduces water circulation and jet action as well. When it"s time to change your spa water, simply remove your filter, add Spa System Flush, then run pumps and jets for a few minutes (or overnight, if convenient). The job is done... just drain away with your old water!! You"ll be astonished at the grime it removes from even well-maintained spas and jetted tubs.