Nice tank! Did you wedge the subwassertang in between the rocks so it wouldn't float? You can also tie it to the rocks using fishing line or thread. Take a look at my 5 gal journal to see what I did if your interested in doing that... it looked amazing (something to ponder). Not sure if I just missed it, but what type of substrate do you have?
Thanks! Yes I just wedged it in there. I just checked out your thread. Man that looked really good the way it spread out. I might try tying it, as it keeps getting popped out of place by nerites crawling on it. Or I might just superglue it. I read that works pretty well.
The substrate is black flourite sand.