Marimo moss bulbs do not consist of moss but green algae. In nature they grow in Iceland, Estonia, Scotland and Japan. Due to its round shape, the Marimo bulb is a popular aquarium plant that is also not very demanding. Marimo bulbs are also real eye-catchers in a glass bowl or vase. Just like in the wild, the bulb does not like bright sunlight and you can keep it nice and round by regularly rolling Marimo between your hands. Unfortunately, there are few Marimo bulbs left worldwide.
The Marimo, not a moss ball but green algae
A moss ball (Cladophora aegagropila or Aegagropila linnaei) comes from the Cladophoraceae family and is not a ball of moss at all, but a ball of green algae. The name “Mari” means bouncing ball, “mo” stands for water plant. Japanese believe that the Marimo sphere brings good luck. Moss spheres can live for as long as 12 years, but in inaccessible areas, moss spheres the size of a basketball have been found to be as long as 50 to 60 years old.
Where do the Marimo bulbs come from?
Marimo bulbs grow in shallow lakes in Scotland, Estonia, Japan (Akan) and Iceland (Myvat ij). In Japan, the Marimo bulbs are sometimes thirty centimeters in size and in Iceland about twelve centimeters, the inside of the bulb is hollow. The algae wrap around an object such as a stone and grow around it. Due to the current in the water, the Marimo bulbs roll over the bottom and thus get their characteristic appearance.
Marimo as an aquarium plant
The round shape of the bulb makes the Marimo moss bulb a popular aquarium plant, the color of the bulb is dark green with a velvety appearance. To maintain its round shape, the Marimo sphere must be turned regularly. The moss bulb is a popular item in nano aquariums, because shrimps love the moss bulbs, they are ideal hiding places for their eggs and food residues easily stick to the bulbs. This is also nice for other fish.
An easy plant
Marimo moss bulbs do not like salt water and you should not put them in the goldfish bowl. Goldfish pick the bulbs apart and that also applies to plecos and large lobster species. The moss bulbs grow slowly and thrive at a temperature of 5 to 28 degrees Celsius. The moss bulb is an easy plant to keep, it is undemanding and purifies the water in an aquarium. The bulbs can reach a maximum diameter of ten centimeters in an aquarium or vase, because daylight cannot penetrate more than five centimeters into the moss bulbs.
Marimo moss bulbs are real eye-catchers
In the United States and Japan, Marimo bulbs are sometimes seen as a kind of easy pet because they are very undemanding and are very decorative in both a glass bowl and an aquarium. In a beautiful bowl or vase you can easily create a beautiful eye-catcher with the help of stones, shells and beautiful twigs. It takes a while before it is large, because a moss ball grows an average of five millimeters annually. You can multiply the Marimo moss ball by cutting it in half and then rolling it back into a ball. To keep the moss ball nice and round, it is best to roll it regularly between your hands.
Care of the Marimo moss bulb
If you take good care of your moss bulb, it can last for years. The water in the aquarium or bowl must be changed regularly, this prevents the moss bulb from dying or rotting. Especially during the summer months, the water should be changed at least once a week to keep the moss bulb healthy. Moss bulbs do not like a lot of sunlight or bright lights, in nature they grow in the bed of lakes where daylight can hardly penetrate. When the temperature rises in the summer, it is wise to move the moss bulb to a cooler place.
You can squeeze out moss balls
If you have recently washed the moss bulb, it may not want to sink, this is due to the air bubbles that keep it floating. Usually it sinks down by itself, otherwise you can give it a helping hand by squeezing Marimo a little under water. The air bubbles will then disappear by themselves.
What does a sick Marimo look like?
A Marimo moss bulb is an easy plant, but if it gets a different color, this is not a good sign. In many cases it is easy to do something about this:
- the moss bulb becomes lighter in color; presumably the light is too bright. Cut the Marimo moss bulb short, it will continue to grow.
- the moss bulb looks slimy and has a different structure; probably another algae has wrapped itself around the sphere that threatens to suffocate the Marimo. Usually you can easily wash this algae off or remove it with tweezers.
- Marimo turns brown; then it is time to thoroughly clean the moss bulb. If that does not help, it is best to carefully remove the dead brown tufts and add some salt to the water. Of course you must turn the moss bulb regularly to prevent the bottom of the bulb from turning brown and dying from too little light.
- the ball turns black; especially the larger moss bulbs sometimes die from the inside. This is easily remedied by removing the black tufts and rolling the remainder between your hands into a ball. The bulb has now become smaller, but usually just starts to grow again.
Marimo bulbs in Akan
In Japan, Marimo bulbs are seen as sacred, they are protected in 2020 because they were slowly disappearing. Around 2000, Lake Akan in Lake Akan National Park still had about two to three layers of Marimo spheres, but due to intensive mining activities, the layers had almost disappeared in the following years. Because of the amounts of phosphorus and nitrogen, the sunlight could no longer reach the soil and the Marimo bulbs cannot live without sunlight. Worldwide there are very few Marimo bulbs left and that is why they are cultivated. Marimo bulbs can be ordered online, but you can also buy them in aquarium stores.