There are appear to be 3 parts to the system: slow dissolving cal hypo; fast dissolving cal hypo; and the imidazolidinone + salt "Shield". There may be additives with the cal hypo tablets that are part of the system, that don't have to be listed, but it can't be cyanuric acid. Likewise the imidazolidinone doesn't have to be listed, even if is the central pillar of the "Sustain" system.
Cal hypo is a great pool chlorinator . . . IF you use it the way I've occasionally described. The Sustain tablets make it possible to use cal hypo via the skimmer, which maximizes the positive characteristics of chlorination by cal hypo.
Actually, as a result of this discussion, I'm considering suggesting that people with metal problems see if they can buy the Sustain blue (slow) tablets to chlorinate with, since their use will have a very positive effect on metal clean-up. The main problem I currently see with this is the extreme high cost for the tabs -- $8 / pound at a1poolfun.com, which is the only online source I've found so far.
Bookmarks