I've done a lot of searching and cant find any posts about algae that look similar to what i have growing in my tank. I have it in the sand bed and on the rocks mostly towards bottom of the tank. Here is a picture of it under white lights. Its covering most of this little island among other rocks. It doesn't seem to get very tall, about 1/2", and is thick compared to GHA and grows in little clusters. Does anyone know what it is? My tank is 2.5 years old.