FWIW I realize that clarity alone isn't the sole indicator of effectiveness. I test pH now and then to verify it's @ 3 or under. Just that since I started using distilled, I haven't measured it over 3 yet.
That was the key inidicator from a 5-star (makers of Star San) interview I heard many years ago on the Brewing Network. (PH Below 3)
The cloudyness you see is the surficants coming out of solution (The soapish part that lets it get into crevices and causes the wonderful foaming). If you leave your siphon hose in there a while, it will get cloudy too... even in RO based StarSan. (Just rinse the stuff off and the hose is fine)
As long as the PH is ok, StarSan supposedly is OK, and I have used cloudy Star San enough times, I would expect that I would have had a major issue by now if it was not OK.
If the cloudy bother you, then RO/Distilled water is the way to go.