I like your rock work, BUT you might wanna make sure that water can flow through the structure. If not you will get stuff stuck in there and it will rot and can cause parameter flucuations.
I have an engineer goby btw, and I know you didnt mean eel but he is an awesome fish. Mine started about an inch long and is now well over a foot. He pokes his head out and digs and is oh so cool. lol His name is teddy bear, cause he has such a sweet adorable teddy bear face. ! LOL
I think mixing clowns would depend on which clowns you have in mind. i wouldnt mix a percula with an oscellaris or a gold banded with a skunk clown. Just depends on the combination.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.