Add a couple powerheads so that you have more water movement and this might change some habits of your fish. Powerheads basically suck the water up and spit it out to create movement. They are made to be used with ugf but most in the reef hobby use them just to circulate water. Now these powerheads have differet ratings on the gph (gallons per hour) they circulate. I have heard that you need to beable to circulate so much water an hour through the powerheads but that is just as disputed as everything is in this hobby.