Thanks @waterbear, your post is again super-informative, I really appreciate it. I've also experienced that finding information reg. Huwa-San is difficult, not sure if their webmaster is just incapable or if, yeah, that's a red flag.
If I may .. could the slow sanitizing effect of silver still be enough for two people using a smallish, private pool? It's really just my wife and me, taking a swim every other day or so. I'm not sure if we need to be concerned about virus contamination, being a married couple. Bacteria and fungi on the other hand are definitely things we want to keep at bay.