I have low light and I have moss growing in places I dont want it. I actually just have been pulling it out this morning. If you look at the last pic on the page for my 10g journal thats linked in my sig you can see. That is peacock moss that started out the size of a golf ball. I have fissidens that started about the size of a dime that is now golf ball sized. Moss will grow fine in low light ime.