<a href=showthread.php?s=&postid=14849821#post14849821 target=_blank>Originally posted</a> by Lightsluvr
IME, it's snake oil -
Just keep your CA and ALK properly balanced, and with adequate lights you'll get plenty coraline without adding crap to your water...
JMHO
LL
<a href=showthread.php?s=&postid=14849902#post14849902 target=_blank>Originally posted</a> by Rendos
Purple Up by itself will make coraline grow. I did an experiment on a tank. I dosed nothing but Purple Up in a new aquarium for 3 months. Coraline covered most of the back wall, and all plastic parts.