Those are some nice acans! I I had a couple when my tank was new, they died because I do not think there was enough in the sand for them to feed on.
It was mentioned already but my sand sifting goby killed a plate coral by always covering it with sand. You will probably have to clean sand off coral daily....
And how are they scolys?I had a diamond goby that cleaned the crap out of my sand and Covered over all my acans. Then I realized... If he wasn't cleaning the sand the Sand around the acans that never moved.... got icky.. So I moved all the acans off the sand and onto the rock work making my tank appear SUPER clean.. and my rock was now brightly colored with acans..
After he had cleaned my sand 500X over.. I basically had zero particles in the water.... I traded him to a friend when I thought that I wanted to place some scolys back on the sand bed.. My sand got ICKY again... So I picked up a mated pair at RedSand and they have been very active and my sand is starting to look AWESOME again.
And how are they scolys?