http://en.wikipedia.org/wiki/Marimo
A marimo ball is a rare growth form of algae, which grows into large green balls with a soft, velvety appearance.
They are native to japan where they naturally grow at Lake Akan. They are also found in Iceland ,Estonia and scotland. They can grow patches on a lake floor at depths from 2 to 2.5 m. The round shape of the marimo is maintained by wave action that turns it.
People often mistake them for living animals because they are usually moving around in the tank.
The growth rate of Marimo is about 5 mm per year.they grow particularly large, up to 20–30 cm (8–12 inches).
All they need is normal household lighting for them to make food, otherwise, indirect sunlight is fine.
You should turn them over once in a while for them to keep their round shape.
Marimo's are actually VERY easy to take care of, probably one of the easiest plants that live in water.
you just have to change the water once a week and your done!" make sure NOT to have age killer in the water!!!!"
{ UNKNOWN FACTS ABOUT MARIMO}
1* They do not float unless the water is squeezed out of them.
2* They are NOT moss, they are a very unique type of ALGAE.
3* They DO NOT DIE when frozen.
lighting
Unlike the idea that they need little light, they do best with lamp light especially if you have smaller, rolled marimo.
if so, they will start to grow outward like they do naturally and look very fuzzy.
They do still grow with little light but if you want fuzzy, healthy ones they need light.
Health problems:
If your marimo turns grey then simply flip it over and make sure the grey area gets light.
If that doesn't not work then you can get a bowl, add water, ice and salt, let them soak in that for about 3 hours .
they are a VERY easy plant ( ALGAE) to take care of and are nice for people that want a plant but don't have the time to take care of it.
They are also a helpfull addition to to fish tanks, thus they act like miniature filters cleaning out the water.
