The Fluval Moss Ball was designed to create a decorative setting, while providing phosphate control. The adsorption resin also helps to reduce many of the compounds that encourage unsightly organic matter accumulation.
Just finished planting my Fluval Spec V. : r/PlantedTank
How To Care For Marimo Moss Balls (And Keep Them From Turning Brown)
Aquatic Moss Balls
Fluval ClearX
My new betta/ghost shrimp tank, Fluval spec 5. So far planted with 2 java ferns, 1 anubias minima, and 3 marimo moss balls and a couple stand in silk plants. He started
Fluval Betta Kit 10L – Reptilian Arts
Fluval Moss Ball, 4.5 cm (1.77)
How often should people change moss balls in an aquarium? - Quora
Fluval Aquariums: Fluval EBI Nano Shrimp Habitat 7.9-gallon