i seriously don't know how i got the anachris to do well, i've tried it over the years in a few tanks and it always ended up turning an ugly brown and decaying quickly and i expected the same thing to happen in my BW tank but it didn't, enstead the anachris remained dark green and started growing a little bit until an infestation of black brush algae over took it completely. i've never heard of anybody else having success with it in a BW tank.