Just be cautious if rock is on the sand. I thought all my rock was on the glass. Today I found out it wasnt. Goby undermined my rock and it fell backwards.
My Diamond Watchman Goby is probably my favorite fish. He has specific rocks he likes to sit on each night. Make sure you have a lid because if he gets spooked he'll jump out. He probably has the most force behind his swim when hes scared compared to my other fish (despite his slow looking demeanor). He likes to "pretend bite" fish if they get close to his hole. This is a slow motion/moving bite that you can tell is doing no damage what so ever, my other fish don't even react to it. My sand is always rearranged, but it's a fish only system so I don't care.