Okay, the story is quite long. While any may read it, I seek advice from ChemGeek and Waterbear. Their Posts proved they were experts and changed my point of view, drastically.
First of all, I am a Pool Store Clerk. Won't name the store, however, we are in the province of Québec in Canada. This means that most of my customers don't speak english and thus I cannot refer them here, nor Poolsolutions.com, nor Poolspaforum.com, etc.
Second of all, the Pool Store is owned by my very own father, and I know personally every other employees. Most Clerks like me are trained by our superiors, who are trained by the various companies we deal with. Recently, one of our two Customer Service Employees, who also was our Expert in the chemicals department, left the company (I think I figured out why, more on that later). As he left, he gave me a task. One of my father's associate asked a report on which of these Systems to adopt (if any): Saltwater Chlorine Generator (Which we already sold), Ultraviolet Sterilizers, Ozone Generators and Magic Chlorine Free Magical Devices.
So there I was researching the subject on those very sites who sold them: Gardia and Cryptosporidium protection... do what chlorine can't by itself... overall fear propaganda. I must admit at that time I was looking at Ozonators with a benevolent eye and laughing out loudly as I read 'bout EcoSmarte. Then I've found this site and those named above.
I was shocked. So many things we weren't doing right, or more exactly, we were doing slightly off. Believe me when I say that my recommendations changed A LOT. It went gradually, I hated using my customers' pools to try out techniques learned on the internet (as credible and scientificaly proven they may be), but somehow it had to be done. There was this one customer which pool turned green about two years ago. Tried any and everything, balanced her pH, alcalinity, different types of algaecides, of chlorine, phosphate removers (yeah, I know, useless), balanced every single parameters she had, nothing did it (as stores sold her for hundreds of dollars of stuff in good faith). Alas, public ignorance could not outdo the problem. So I took the opportunity. If BBB combined with Cyanuric Acid could bring back that Aboveground Swamp, it would be what I'd recommend from now on.
So I did every tests you guys recommend (although CH wasn't necessary), found nothing to balance but found out there was a presence of Cyanuric Acid in the water already (around 30-40 ppm) as she even tried in some pucks for a while. She already had at her disposal a nice big jug of liquid chlorine. Her test was oTo (which I was glad) So I told her her chlorine had to be strong enough to actually get a false reading (Red / Brown instead of yellow) around the clock, so to check the chlorine levels at least thrice a day. It took some time, as her Sand Filter must have been clogged with green/yellow algaes, but, after a week, it took care of it, leaving a trace of brown algae in the pool.
But now, I am stuck with another problem. Our Pool Store tries to keep a good reputation, that is probably why we do not and won't carry any other system than saltwater, however, I am stuck between ''telling the truth'' and the misinformation's income. Don't misunderstand me, I am all for the BBB / Cyanuric Acid method and try to talk out of Trichloro-s-whatever as a main chlorination method as often as I can (seems like Overstabilisation does cause quite a lot of those problems we were ''unable to solve''). I also mentions that our cheap chlorine (50 $Canadian for 16 kg of 65%) and HtH are Calcium Hypochlorites and that it raises Calcium Hardness. This can cause a white paste to build up over your sand and in your pipes and that when it'll go off this'll mean a milky pool. When they ask me what I recommend I talk about Liquid Chlorine and mention it is JUST LIKE BLEACH (Sodium Hypochlorite). Peoples buy it anyway, because they had to pick it up right now, because they don't want to go over to Wall Mart (which isn't THAT far), because they don't want to carry tons of Jugs as ours is more concentrated, but sadly I cannot talk them out of that without harming the company I work for, my standings within said company and thus my influence into changing said companie's behavior.
Needless to say, my recommendations were as follow (but in french):
''U.V. Sterilizers and Ozonators are wonderful for killing those chlorine resistant bacterias inside THEIR CELLS. When Cryptosporidium and Gardia taint a pool, yeah, chlorine won't kill it fast enough to prevent infection, but those two systems won't either. Before all the water of the pool goes into the cell once there will be AT LEAST a few hours, more than enough to infect everyone else in the pool. And that doesn't even make it safe. Guardia will have been Oxidized in the meantime anyways! This means (insert potential companies to deal with) are using fear and misinformation to sell. I doubt we want that kind of marketing here at (insert own companie here).''
Note that I haven't mentionned anything about spas however. A lower amount of water and a good circulation rate might make those systems efficient (but I doubt it), so without evidences I kept my mouth shut.
So now here I am, solving problems like a renegade pool clerk, giving this internet address to ANYONE who do speak english, summarizing it up for others. My wish was our company publicly councilled peoples to go to Poolsolutions.com, as I quote:
''But, if you do find someone who knows pools, and is not trying to load the Monsanto's entire 1998 chemical output into your trunk . . . well, then it's worth the extra bucks. Just keep in mind, what's worth money is not what's in the bucket, but what's in the dealer's head . . . and heart.''
[EDIT] Reason why the other guy would have left: Very very aggressive Pushing sales technique by Natural Chemistry. I don't know the details, but we felt the repercussions in the misinformation it spreaded ''As soon as there is a SWG in a spa, tests for Phosphates. By allowing algae to form, it drains the spa from chlorine generated, the Cell may be overworked and fail and blah, blah,blah... with my superiors all too eager to believe.) [EDIT/END]