A scourge in our tanks.

[Slipper]

They look cute and cuddly. So unassuming "just plop them in". But the next thinhmg you know you're pulling thick strands of algae for a year.  I am refering to marimo "moss" balls. I bought a bunch(20) for my rhyzome themed tanks. Well the algae, they are, has invaded!  It is choking out my java fern,  anubias and african water fern(bolbitus)  and buces. I cannot keep ahead of it. Take my word burn them with 911 jet fuel or ship them back to the lake in japan. Anyone have any advice on how to get rid of this algea? Maybe a light intervention? Seriously though, worst ever first world problem.