I keep sea lettuce and chaeto in my sump for nitrate reduction. I have a kessil a380 refugium light hanging about 15” from the water surface. The light is on for 10 hours while tank lights are off. I’ve notice the sea lettuce is turning white on the surface of the water. Any lettuce submerged is green and seems to be increasing in mass. I’m I burning the sea lettuce creating more nutrients or is this the color for sea lettuce when it starts to grow. I have noticed some nitrate increase.