If one is going to use a metal ion system, and I'm not recommending that, it should be a copper/silver combination system so that at least one gets some control of fecal bacteria. Technical details and kill times for chlorine, copper and silver are found in this post. So these bacteria evolved mechanisms to handle low levels of copper ions. This is because the level of copper ions in your gut where such bacteria live (in controlled numbers by other more beneficial bacteria and immune system components that keep them in check) has around the same level of copper ions as in a pool (if not higher). So, there's no savings for a BBB method user, just more expense and more stains.Д¬opper not only kills bacteria more slowly than chlorine, but at the levels allowed in pools copper ions do not kill nor inhibit fecal bacteria AT ALL. (Copper, not chlorine, causes green hair.) and without staining your pool blue-green or your hair green. The companies themselves have stopped doing this, though only after several got hauled into court! But apparently, a lot of sales reps still make those claims, because I keep hearing them from people here.Д«UT, if you are a BBB method user, you've already reduced your chlorine use MORE than 50%. When people claim you can run a safe chlorine-free pool with 'minerals', they ARE scamming you. Copper is not a sanitizer, because it does not kill viruses and is too slow with bacteria. Unfortunately, 'mineral' products often turn into a scam when sales people talk about 'chemical free' or non-chlorine. So, I wouldn't call it a scam, not quite. So, yes if you used a 'mineral' system faithfully, your use of chlorine would be reduced, perhaps 50%. My point? A typical pool with a lot of copper is less likely to have an algae bloom than one with no copper. PoolForum pools don't usually have algae messes, and when they do, they usually get cleaned up quickly. In average pools (ie, non-PoolForum or BBB method pools) 50% or more of the chemical use in a typical season goes to cleaning up algae messes.

In today's swimming pool market 'mineral' = 'copper' or sometimes 'copper + silver' or rarely 'copper + zinc'.Д¬opper kills algae.

Frog leap system for pools