Can't really tell with mostly blue light on but looks like both, cyano on the rock to the left and diatom starting on the white rock. Where did your parameters settle too now? How long do you leave your lights on? If you have corals you can reduce like a couple hours of light for a few days. If just Fish and live rocks leave the lights off for a day or two. Are just starting up the tank? What do you have in you tank?