EzSystem Flush Spa Cleaner should be used before the water is drained from your spa or hot tub (typically no longer than 3 months for domestic spas and hot tubs although heavy use will require more frequent drains).
This product is specially formulated to clean all the pipework and fittings by loosening biofilms caused by build up of soap and oil deposits which can provide an ideal environment for bacteria.
Easy to use. Full instructions on the side of product.