Please don't squeeze them. I had a beauty which was the nsize of a baseball and it was fine then people said to squeeze and after a few times of squeezing it cracked then eventually fell apart.
I left it in pieces for over a year hoping it would grow back into a circle or something but no, it didn't die either. So I read about people attaching it to DW and tried the DW thing. It worked alright but eventually I had a pH crash and lost them.
Now I got a handful of tiny ones from a lfs a couple years back and they were the size of a small marble or a couple a little smaller. After 2-3 years they are the diameter of a quarter and a little larger I use a chop stick to push them around occasionally to help them stay round.
Here are a couple pics.
This is a big one I had, lower left corner. Floating one on an anchor had a foam cor with Java moss covering it, not the same as a Marimo Moss Ball
3/14 you can see one of them
6/14 here are the moss balls about half grown to now
3/15 Here the same 2 Marimo Moss balls are floating. Rally had grown. They were given supplemental lighting when my light fixture wasn't working properly in my 6.6G Edge tank, and floated!!
Here is a bowl/jar scape and note the tiny one in the front...The wood as 2 pieces laid over it center and to the rear side.
I do cup them in my hand and lift my hand above the tank and let the water drain out every once in a while like every few months or more and then set it back where I want it.. Shrimp love them and keep them really clean - Amano and dwarf shrimp.
Lower left corner ~3 inches this one has appx doubled in size.
