Normal levels of chlorine, especially with CYA in the water as would be the case when using Dichlor at least some of the time, will not eat up or corrode the copper or silver -- at least not very quickly. After all, copper is used in some gas heaters in heat exchangers, though they do not last as long as titanium or cupro-nickel alloys. Copper piping in homes is quite common and does not corrode quickly in spite of chlorine (with no CYA) that used to be used in the water (now monochloramine is more commonly used). Low pH is far more destructive to metals than chlorine levels, though high chlorine levels (such as high chlorine without CYA) combined with high conductivity such as from high salt levels can be corrosive.
In some systems, copper and silver are converted from metals to ions using electrolysis, but in Nature 2 it sounds like they use compounds where the metals are already ions and are dissolved or dosed via water flow or where the water flow powers electrolysis (they aren't clear on their website about this -- they say they are not ionizers, but then talk about being "powered" by water flow). Nature 2 for pools uses silver and copper while Nature 2 Spa uses zinc and silver. That's a good thing since spas tend to rise in pH a lot and using copper would result in green water a lot of the time (from precipitating copper hydroxide and oxide). The Nature 2 Spa owner's manual here indicates that Nature 2 Spa is not compatible with bromine, sodium bromide or biguanides (e.g. Baqua). It is intended to be used with chlorine and in fact must have at least some residual amount of chlorine. After you balance the water and install the cartridge, the instructions say to superchlorinate (they call it superoxidation) by using Dichlor. So clearly their product is designed to be used with chlorine, even at shock levels. Their low-chlorine procedure uses mostly MPS with chlorine for shocking as needed though they also indicate that the daily MPS may be substituted with Dichlor (chlorine).
Richard
Thanks for the info. Richard. Ive been using 6% non sented bleach as you have talked about in other posts and so far things have been looking good , keeping my chlorine levele at 2 to 3 ppm I was using the diclor daily and got very dry itchy skin, we'll have to see how it goes with the bleach, also I guess I will put my natute 2 cartridge back in. Thanks again.