Welcome Gold Head Sleeper Goby "Hoover"
New very interesting fish added to my tank. I had a problem with my rocks going brown a couple of days after cleaning the tank, I needed something to turn the rocks over. I was going to buy a star fish but the aquarium shop said they don't move a lot of rocks, they're quite lazy. So this awesome little guy was perfect.
Within a day all my rocks were nice and white. What he does is picks up the rocks in his mouth and they come out through his gills, its amazing to watch. Some people say they drop the rocks all over they're coral, but so far he is behaving. He has only done it once when he had a mouthful and another fish scared him and he swam away dropping it as he went.
You need to supplement these fish's food, you can't rely on it getting all he needs from your substrate. He loves marine dinner, which is a mash of frozen food, I burry it just under the surface near his cave and he digs it up. When you buy a goby make sure you ask if he is eating frozen food, even get them to show you. If he wont eat frozen food he will starve in a couple of months.
My other advice is don't siphon your rocks, leave it to this guy. When you siphon you suck up all the critters he would love to eat.