How exactly does it work? Do you need to use it in order to get a certain fin type? I have ALL crossbreeds for all fin types EXCEPT that particular one (the one where there are NO FINS) ... so how does it work? I tried it once in my sell tank but only ONE fish changed body type ... not fin type ... it is pretty expensive for THAT kind of response!! Up to now, I've done it all on my own, not glancing at anyone else's charts, but until I find an answer, I'm pretty much at a standstill... HELP!!