Will this help?

The company I work for has assembled a 10,000 gallon fresh water tank that will be in constant use. It has been painted on the exterior but not the interior. Would dropping a couple bars of zinc or magnesium into the tank slow the formation on rust on the insides of the tank? The tank is all mild steel, though vents and valves may be of an alloy.

You need someone who is fluent in the study of metal and their reactions in aquatic systems, would be my guess, not a home inspector.

this company may have an answer

The zinc or magnesium bars are known as sacrificial anodes. They use them up here for protecting buried pipelines from rusting, and yes it works, but it is a designed system, calculations are done to determine how much to use and where to put them, AFAIK they are fastened to whatever they are protecting, not randomly dropped in.