I have a question about growing coraline? As you can see from the photo, I have no problem growing it. But, why can't I grow it all the way up the back glass? I have about 3 inches from the top, straight across it won't grow? Why would it do this? I do have a tuxedo urchin and linkia starfish but don't notice them hanging out in this area. Any thoughts on why it won't grow here?


