Using Potassium Permanganate, which is an oxidizer in both a control tank (left tank) and one utilizing an AAP Compact UV with a HO UVC Lamp (right tank).
This of course is a simplification, so please read the ENTIRE article along with cited references for a better understanding so as to make a more educated decision of whether a true high dwell time UV Sterilizer is for you or maybe just a Clarifier or nothing at all!
Ultra violet sterilization is an effective tool especially when combined with other tools such as new fish quarantine (or new fish baths) for disease prevention in aquariums, ponds.
Also for general water quality control such as Green Ponds or Cloudy Aquariums.
The UVs I promote cover different niches from lower end to higher end.
One thing all have in common is they work within their niche.
That covers the visible spectrum and immediate neighbors, all the colors are between about 450 (blue)-700nm (deep red to near IR).