storage

Ultra Biocid is a low corrosion product, but it is also very low pH and as you know low pH aggravates corrosion particularly existing corrosion cells. What happens in the metal piping is that areas where corrosion is most likely to occur, that is heat affected zones (HAZ) of welds, crevices, existing pits, galvanic couples (i.e. like screws or bolts that are different metals than the base, as well welds where the weld rod is different than the base), these areas actively corrode.
The best solution because it is the most economic solution is to re-pipe with schedule 80 PVC piping. The PVC is inert to Ultra Biocid and as long as you don’t need to pressure the line excessively or run the Temp above 140 F it is perfectly safe. Schedule 80 PVC runs about $100 for a 20 foot section add in coupling and elbows where needed and you can run a lot of PVC fairly cheap.
As to the tankage and storage again PVC or polyethylene/propylene tanks are best for the same reason. The bulk tank (metal) probably will not corrode a lot, but couplings and welds where HAZ exists or flanged fittings etc. probably will corrode. You can investigate lining an existing metal tank, but to be honest I think it will just as economic to purchase (perhaps used) a poly tank and pipe it up with PVC.

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