Stainless steel water tanks

Thanks Kezza. I thought that might be the case. The less things to worry about the better.
Cheers.

From experience Ill never put anything acidic or alkaline inside a metal tank, stainless or otherwise as any imperfections may react and oxidize, you will then have continuing problems with water quality and the tank.

Its just Ok for plastics -polypropylene or polyethylene, - if you can flush it out OK. best to use a sterilizing agent like in home brew kits in plastic(again not in metal)

I know its tempting cause its sooo easily made but nobody should be using PVC pipe for storing drinking water let alone using Oxidizing agents to clean PVC as it can release toxic chlorides.
(I spent some years in the plastics industry and know people who would not have and Poly vinyl chlorides(PVC) in their factories let alone store water in them)
go the distance in good health

kezza