As described in
this link, the Artesian Spas Crystal AOP Water Treatment is a combination of Nature
2, UV, and ozone. The Nature
2 silver ions if used alone without non-chlorine shock (MPS) provide slow disinfection rates as shown in the chart in
this post but should be enough to prevent uncontrolled bacteria growth for some bacteria. Their site says that Nature
2 provides copper ions, but that is only in the pool version of Nature
2 while in the spa version there are zinc ions instead. Such ions are not effective against viruses and generally won't kill fast enough to prevent person-to-person transmission of disease which is why such a system would not be allowed without a disinfectant such as chlorine or bromine in a commercial or public pool or spa.
The UV if used after the ozonator will produce more hydroxyl radicals which are powerful oxidizers (some are produced anyway when ozone breaks down but more are produced when UV is used). This could help the spa clear in a more heavily used spa if enough ozone were to be used. It also should reduce the rate of hot tub cover degradation as there should be less outgassing of ozone. They have a fast circulation pump to circulate the water fairly quickly, but remember that some pathogens stick to spa surfaces and grow there so while the silver ions may help to inhibit that growth, the UV/ozone won't do anything unless residual ozone got into the spa water (and with the UV system after the ozonator that should be less likely to occur).
The more usual way to use the Nature
2 system as described in the
Spa Mineral Sanitizer Owner's Manual is with non-chlorine shock (MPS) and this combination is approved by the EPA for disinfection.
