I've actually stopped using it recently (a couple of weeks ago), I suspected that it may be causing or aiding some stn type recession on a couple of my more picky acro's. Don't know if it was the purigen. But I took that out first because it's the only "unconventional" thing I had been using, and water parameters were all fine.
I wouldn't think it would cause problem, all it is is a polymer. I'll probably put it back in later. Who knows, maybe it was just that time of month for these particular acro's. It tends to be the same ones I have intermittent problems with, but they seem to recover quick enough.