beautiful! what's that on the back wall, lettuce nudi or somthing? i really like your rock-scaping, especially how you kept it off the back wall. it looks so cool from the long way.
Hwarang - It is a lettuce nudibranch. I don't know how but it got injured a couple of days ago. It has been in a really high flow area and slowly getting better.
Meloco14 - It is Natural Wonders Black Calcite sand.