Marimo Moss Ball

Marimo Moss Balls aren't moss at all, they're a rare freshwater algae species that rolls itself into a soft velvety sphere over decades in the wild lakes of Japan and Iceland. In your tank they act as a living nutrient sponge, pulling nitrates and phosphates out of the water while giving shrimp, snails, and betta fish a squishy little toy to nudge around. Zero substrate, zero lighting demands, and they'll outlive most of your other plants without complaint.