There is a copper based product out there called Pristine Blue that has been on the market for years. It is copper. At low levels (0.2 ppm), copper kills algae. At higher levels (0.4 ppm) copper can kill bacteria. However, levels above 0.4 ppm copper will cause stains at normal water balance levels. Therefore, when using these products you must maintain a lower than normal pH and alkalinity or you will get staining. Too high copper causes stains, too low copper and you do not kill algae and bacteria. You must test for and maintain the proper copper level.

These products only kill algae and bacteria so you must also use chlorine or a non-chlorine shock treatment to destroy ammonia, nitrogen compounds and swimmer waste. Keeping a 0.4 to 1.0 ppm chlorine residual is usually recommended with these products. Most people realize that if they are going to maintain a low chlorine level anyway, why not just raise the chlorine a little higher and forget about using the copper and its hassles.

Ionizers do not address the problem of swimmer waste (sweat, urine, saliva, skin cells, body oil, etc.) These things are not removed by filtration nor are they destroyed by copper, silver or zinc. They must be destroyed or oxidized by a separate oxidizer.

You either need chlorine or a non-chlorine shock such as monopersulfate. In ionizer systems, it is recommended that you maintain a 0.5 ppm chlorine residual. This is to oxidize the swimmer waste and ammonia AND to instantly kill bacteria and algae.

Copper and silver are slow to kill. Chlorine is fast. Maintaining a 0.5 ppm residual is hard to do. A few bathers and the residual is gone. A little sunlight and zap. Most people end up just maintaining a 1.0 to 1.5 ppm of chlorine. They will use less chlorine than without the ionizer.

The other problem is the amount of copper in the water. Too much and hello stains. Too little and bacteria and algae can grow. Then when you notice the algae growing it is too late to crank it up. Depending on the ionizer manufacturer, you need a minimum of 0.2 ppm copper up to a maximum of 0.5 ppm copper. The 0.5 ppm of copper is a stretch. At normal pH and alkalinity values, 0.4 ppm copper is the max you can have before staining occurs. To have 0.5 requires a lower than normal pH or alkalinity.

Ionizers can be and are used successfully. It requires close monitoring of the copper level - weekly, the chlorine level - 3 times a week, and the use of a separate oxidizer - weekly or more often depending on bather load and chlorine level. In addition, pH and alkalinity levels must be kept in the proper range - weekly.

Secondly, copper does not destroy organics or swimmer waste such as sweat, urine, saliva, and other bodily fluids. You must add a separate oxidizer to remove these things. How often depends on bather load and organic buildup. You could need an oxidizer every day or a couple of times a week.

Copper is copper. It is no different than a copper ionizer or a copper algaecide. In fact, ionizers in most states are required to use 0.5 ppm of chlorine along with the copper. (For the above reasons.)