Buying Marimo Balls Online
Marimo Balls are listed as a special Japanese Natural Treasure. Sometimes non-balling moss such as Java moss is rolled together around a ping pong ball and sold as Marimo balls. So remember it is buyer beware. Do your research and only purchase from reputable online sources.
You also need to remember that these are NOT plants. These cute balls are actually a colony of algae. So, if you use chemicals, medications and even some mild forms of fertilizer, you may accidentally cause your colony to die off.
Marimo balls grow very slowly. A 10 or 12 inch diameter can only be attained under ideal natural conditions. The largest reported Marimo ball in an aquarium is 5 inches in diameter. So if the vendor claims that the Marimo ball will grow at phenomenal rates, look elsewhere.
Be sure to check on the method of shipping and whether or not it will be insured. Insured registered mail can take two weeks or more to reach its destination. Marimo balls have been known to survive extended periods of time in transit, but remember, the longer your algae is packaged, the greater the risk of damage.
How can you tell if you have a genuine Marimo ball and not just a fake ball of Java moss? A Marimo ball should feel a little rough when you run your fingers over their surface, but should be soft and spongy when you squeeze them. After squeezing one, place it back in the tank. It should float for a few seconds and then sink to the bottom. If it is a fake ball you will feel the hard ball (most likely a ping pong ball) inside and the moss might even peel away. Fake balls will always float.
Below are listed a few online stores that claim to sell the real Marimo balls.