Whitlam Flow-aide Solution, 1 gal 1 gallon of flow aide system descale Non-toxic concentrate which is certified to NSF/ANSI 60 for use in potable water systems Combining flow-aide with isolation valve kits (service valves) will make the descaling process easy Water scale deposits are a significant cause of heat transfer loss Even a thin layer of scale (1/32") can cause a 30 percent in the cost to operate a hot water system