We were asked a question that needs to be answered in more than one line. When we have such a question I like to make it into a blog, and let everyone share in the answer.QUESTION:Answer:Mario Ballsare composed of an algae belonging to the genus Cladophora that is commonly found in aquatic systems growing on rocks or in aggregate form.In certain environments where centrifugal forces are strong, the algae is rolled into balls, which is where we get Marimo balls.They provide a surface for biofilm grazing as well as limited denitrification.Common myths regarding Marimo balls include:- They clean the waterAs an algae,Marimo Ballsutilize Nitrates and other nutrients from the water column, but since they are relatively slow growers, they do not provide substantial denitrification. They will not prevent water changes- Nothing does. They do accumulate debris, so remove occasionally and rinse by squeezing repeatedly in clean water until the sediment is removed. - They prevent algaeMarimo Ballsare an algae! They can provide competition for other algae, but that's as far as that myth can be stretched-Marimo Ballsreproduce by popping off smaller, baby Marimos.Marimo Ballsdo not. They are simply a ball of algae that only reproduces by growing more strands within the ball. If you want to make new Marimo, you must split the parent ball and roll individual balls. A powerhead in a bucket helps build the ball shape by providing that centrifugal force. Retail workers come up with some pretty inventive ideas regarding Marimo Balls, but the truth is simple. They are neat little things that have substantial meaning in Asian culture.