It's great as a conditioning food for just about any rainbow I've ever
kept. As for culturing it successfully the most productive methods
would likely involve something outside. I do know of a guy who is able
to keep strong cultures going because he can provide a vigorous
green water culture on which to feed them . If you can find a sunny
spot to grow green water in a 15 or 20gal tank you should do ok with
them.
I'm sure there'll be more thoughts on this.
Chris