I can see your lights but not to well. Are they just PC's. Open Brains like Strong Lighting and some flow. So unless you have Metal Halide's I would move it up towards the top half of the tank. Before you do that though. I would take it out and give it dip it in a coral bath. Let me know if you need to know how to do that.
I see you have a clam next to him thats closed up. If he's always closed like this, then move him up to the very top of the tank. Clams like REALLY strong light. If you were to reproduce the light output most clams receive, you would have to put the clam under about 8in of water under a 1000W bulb. Crazy right?
Also, the stores tend to check for calcium, but not stronium and magnesium. These two are just as important as calcium for coral health and growth. You have some coraline which quickly uses up magnesium. Check out those two levels. I would use products made by Natureef they seem to be the best.