Once I'm not so busy I'm going to read through those articles, thank you. I had only read "Benefactor or Bomb" before.

Residential indoor pools around here use a FC reading of 1-3 ppm normally. When using a SWC they normally do not ever 'shock' the pool, either by means of the SWC, liquid chlorine of monopersulfates. We test the water for them monthly and always have 0.0 ppm CC using FAS-DPD test kits. Customers that have used their indoor pools for years without a SWC almost always comment that the "chlorine smell" is gone for good once the SWC is running. New pools built with SWC's never mention anything about the smell, leading me to believe that it isn't there at all, and they just don't realize the difference the SWC is making.

Commercial indoor pools use a FC of 4-8-ish when using a SWC. We don't have inspectors around here to check, and our city (120,000 people) does not require anyone to have CPO training. We try to offer training as much as possible for our commercial customers, but we can't teach everyone everything. When we set up a new commercial pool with a salt system, we include pH and ORP controls so that they are never out of the proper range. As far as I know, these customers also do not 'shock' their pools.

For non-SWC customers, I would guess they have some CYA in their pools; from pucks. There are at least a few places that have used pucks, liquid shock, cal hypo, algaecide, flocs, coagulants, and monopersulfate - ALL in the past year. They will often let the chlorine drop to 0, the pool goes cloudy, they add a bunch of algaecide, clarifier and monopersulfate and when that doesn't work, they call us. We pour in some liquid chlorine and it clears up. They hardly listen to what I have to say, and do not feel that a SWC system would be worth the money. They are just content to have their pools shut down for a day or so every few weeks. These pools always have a strong chlorine odour; they just do not understand what they are missing.

I believe that most of the indoor pool related health problems, such as asthma, are related to combined chlorines. I also think that most corrosion of indoor pool areas is from CC's. I remember Sean saying once that they tested the chlorine inside their cell at above 80 PPM. This would suggest a constant shocking happening inside the cell, reducing combined chlorines. I think that when combined chlorines are gone, most of the health problems and corrosion of pool rooms dissappears.

Brad