I have an algae issue on one side of my tank/sand only. Is this normal, or could there be an issue with one of the lights? I am using 2 radion xr15 pros, which should have identical settings. I am also using 2 reefwave 45 gyre pumps mounted at the top-back, pointed to the front & slightly down. Both have fluctuating flow patterns, but the same max speed and direction. Thanks!