3-4cm Marimo moss balls are very low maintenance live plant. Marimo act as a filter and require cleaning from time to time. Marimo can have different colors depending on the depth at which they grew. In the aquarium after 3 weeks they will look the same. Sometimes You can find grains of sand. You can put them into a separate water container and squeeze them very gently few times in your hand. This is the way of cleaning them. You can repeat it every 10-12 weeks as they work as filters. If you will not do it after 12 weeks its not a problem. You will be able to see if they need cleaning.

Great for getting rid of pond algae and algae in the aquarium because the moss ball out competes the algae for nutrients since they have similar diets. Also in your pond drop a couple in and let them remove nutrients that cause that ugly green water. This will also let you get rid of algae the natural way. They clean water, don't make it cloudy.