I've had the same results, and I have bad filtration. I must do extra cleaning of the filter to start with, but the water does sparkle. The stuff is magic! Plus, when buying it from Gene it is here lickety split!
I've also had good results with it. I'm cycling a new biofilter and had the dreaded "green water" syndrome. It's gone now, and the string algae infestation that was starting up has fizzled out, as well.