The Science is Solid: CD Ozonators are Superior Spa Sanitizers
The Corona Discharge (CD) spa ozonator, first brought to the mass market by DEL Ozone in the mid-1990s, was a technology breakthrough that changed the game in spa sanitizers. For the first time, spa sanitation became truly automatic with the reliable and powerful CD chip technology used in DEL’s CDS-16 and Spa Eclipse™ (ECS-1). Spa chemicals and chemical alternatives became obsolete as primary spa sanitizers.
DEL continues to innovate CD technology. In 2001, DEL pioneered the CD electrode technology for spas with the HO ozone generator and MCD-50 ozonator, boosting both ozone output and length of service (to about 5 years). DEL continues to develop new approaches to ozone sanitation to improve power and reliability at even lower cost.
Independent science shows that the CD ozonator technology is a powerfully effective oxidizer for sanitizing hot tub water. It works against a broad range of contaminates and even contributes to the clarity and freshness of the water.
Alternative Sanitizers vs. CD Ozonator Technology
During the past decade, a number of competing technologies for spa sanitation have been marketed, including popular chemical alternatives. The following table is a summary of the features of these sanitizers. Below the table you will find some explanatory notes about the sanitizers’ benefits.
| Sanitizer Benefits: | CD Ozonator | UV Ozonator | Chlorine/Bromine | Alternative Chemicals | Ionizer |
| Sanitizing Power | Very High | High | High | High | High |
| Sanitizing Range | Very High | High | Moderate | Moderate | Moderate |
| Algaecide | Some | Some | Yes | Some do | No |
| Bactericide | Yes | Yes | Yes | Some do | Yes |
| Oxidizes other organics | Yes | Some | Some | Some | No |
| Eliminates chloramines & bromamines | Yes | Yes | No | No | No |
| Helps water clarity | Yes | Yes | No | No | No |
| Micro-flocculant | Yes | Yes | No | No | No |
| Carcinogen | No | No | Yes | unknown | No |
| Environmental Impact | None | Yes | Heavy | unknown | None |
Explanation of Sanitizer Benefits
Sanitizing power: Ozone is 200 times more powerful than chlorine as a primary sanitizer.
Sanitizing range: Ozone is effective against the widest range of hot tub water contaminants – see the remainder of the table. The CD ozonator technology is capable of injecting more dissolved ozone into the water than the UV alternative and leaves a higher residual level of ozone that can oxidize a wider range of organics (though the residual is small since ozone oxidizes on contact and is quickly reduced to ordinary oxygen).
Algaecide: The one place chlorine may be most effective. This is more important for a pool than a spa because of the much greater volume of water. Algae can bloom any place in the volume of water, and if it does not come in direct contact with a sanitizer that is effective against it, it grows. Ozone kills algae on contact, but ozone is injected in the circulation system and oxidizes so fast that any uncirculated water may contain algae. Chlorine shines here because in solution in the body of water it is present everywhere so it prevents the algae blooms.
Bactericide: All sanitizers should be effective against bacteria and viruses. However, ozone kills 99.99% of bacteria and viruses on contact with no harmful byproducts.
Organics oxidation: Ozone oxidizes a very wide range of organic materials, including human bodily fluids, oils, cosmetics and materials introduced through the air. Some other sanitizers, like Biguanides, are not effective against these contaminants.
Eliminates chloramines: One possible byproduct of chlorine is chloramines. These compounds account for the red eye irritation in swimming pools, and can sometimes occur in hot tubs. The only spa sanitizer that can neutralize these compounds is ozone.
Help water clarity: The only byproduct of ozone is oxygen. Adding oxygen to water adds clarity and sparkle and freshness.
Micro-flocculant: Ozone acts to encourage the grouping of minute pieces of organic material in hot tub water which allows the filter to trap them and eliminate them.
Carcinogen: Chloramines, a byproduct of chlorine, is proven to be a carcinogenic material.
Environmental impact: The only byproduct of ozone is oxygen. Chemicals leave residues that affect water quality or must be disposed of in the environment.



