I think you [RT] bring up a good point about preventative flushing, and that's what I don't like about FF- after a while, components interact adn salts actually fall out of solution. An old bottle will RATTLE when shaken, lol!
That TriFlex is Botanicare's bottom of the barrel entry-level granular dry fert. The only time I'd consider running it is on an outdoor remote grow (even then I'd probably not rely on it for all the fert needs, and supplement it with a seaweed/humic tea), because it is lightweight to carry out into the bush.