New pool owner, need help getting water right

[amber]

Did you get my email?

[PoolDoc]

Sorry, yes I did.

I was having a discussion about it with several senior forum members . . . and then forgot to come back here.

Bottom line:

1. As best we can tell, the PPG Sustain program with "Summer Shield" is based on a class of chemicals called imidazolidinones. These can be combined with chlorine to 'store' chlorine in the pool, in a relatively inactive form that tests as combined chlorine. PPG has a expired patent for their use in pools: http://www.google.com/patents/US4681948

2. This system is largely untested for human safety. This is probably why it is allowed solely for experimental purposes in Europe and Australia. Untested does not equal unsafe -- it just means nobody knows.

3. Normally, a sanitizer system, based on a different chemical set (chlorine + imidazolidinones), would have to be registered with the US EPA as an approved pesticide (sanitizer). This is an expensive and difficult process. PPG appears to have ducked this requirement by having YOU combine the chlorine and imidazolidinone, by adding them separately to the pool. This is not a new idea in the pool industry: the ammonia based mustard algae treatments employ the same tactic.

Please understand; this is not a criticism of PPG. The EPA requirements have made it so expensive to introduce new sanitizers and algaecides to the pool market, that no one has done so in probably 25 years. The pool market is just not large enough to justify -- to most corporate accountants -- spending millions of $'s for R & D and testing, on an unproven product.

It's also not necessarily a criticism of the EPA. The EPA is a huge bureaucracy, and like any bureaucracy, engages in a lot of behaviors that make sense only when seen from the point of view of the individual career-saving moves of many bureaucratic 'ants' within the anthill. So, the EPA inevitably does stupid things -- like all bureaucracies do.

Is it worth it to make sure that the products that DO get through are safer, at the cost of making sure that the only NEW products that are developed have a huge potential market? I don't know.

But, in this case, it does mean that there's very little published information about either the safety or the efficacy of chlorinated imidazolidinones.

4. BUT. (And this is a big BUT)
But, there is nothing in the Sustain / Shield literature that seems to me to offer ANY benefits beyond what you would get from running what I have called a high C2 program: high chlorine + high CYA or stabilizer.

You can use the K2006 test kit to run CYA levels >100ppm, and use the Best Guess chart (link in my sig) to do the exact same thing PPG is trying to do with the Sustain program: keep a large amount of chlorine in reserve, but immediately available.

Doing so would be
(a) a LOT cheaper;
(b) use WELL studied chemicals KNOWN to be reasonably safe;
(c) cut you free from your Sustain dealer


By the way, thanks for bringing this up. Several of us have wondered for years what Sustain was, and have speculated on various possibilities. But this time, for whatever reason, Chem_Geek, Waterbear, and I put our heads (and our Googling abilities) together, and worked out what I'm 95% sure is the correct explanation of all this.