I've been looking into these home water purification systems. A good one will strip pretty much anything out of the water, so as a window cleaning company that used their own water to clean the glass put it, its dead water, in theory nothing can survive in it. Now to touch and feel that "dead water" it was like handling liquid silk without the thickness or resistance. It would be like having the most luxurious bath or shower you'd ever have without any cleaning products like shower gels, bath soaks etc. It also means the amount of cleaning product used, like washing powder for clothes, shower gels, dishwasher product, goes down and becomes more effective as there is no mineral to interfere with it. Technically pure water is an acid.

Anyway I have not found any suitable answer for cleaning the water pipes after these strip everything out of the water filter systems, and whilst it shouldnt be a problem if you have copper pipes throughout the house because copper kills most bacteria and some viruses, hence copper water vessels from the past, if you have the new plastic flexible piping in the house, cleaning will almost certainly be required.

Penicillin based antibiotics when they are broken down in the liver become penicillamine and this causes the body to release lots of copper into the blood stream, so how much is that having an antibacterial effect on the body? Plus copper is also needed for interleukin-6 which kills alot of cancer, so if doing lots of penicillin antibiotics, your risk of cancer could go up if your dietary copper intake is not high! Something the medical professionals dont tell you!

So something like what the pubs use to flush their pipes leading up from the barrels and kegs should do it for cleaning the water system pipes after the water filter, but like I say, I havent found anything satisfactory from these household water supply filter people. Certainly copper pipes are best though, and if doing some DIY, dont leave any flux on the pipe because in damp cold conditions, condensation reacts with the flux and it causes tiny pinholes to form in the pipe. A good plumber will clean their pipes down to stop this from happening otherwise you get minute water leaks that can get worse very quickly.

UV-C is the main disinfecting UV light source, but you dont want to go near it because UV-C destroys pretty much anything which is why most of it is blocked in the upper atmosphere.

I know hospitals use it to clean wards and rooms, but it will destroy materials much more quickly, ideally hospitals would clean a ward and room like normal to remove ground on dirt and then use the robots that move around shining UV-C all over the place.