The biowhels on a Emporor400 sometimes get rotated to fast. Try slowing the spray to them and you will notice a thicker biomass. Also, I used to fill the chambers with biomedia and had a sgonge filter on the intake. Works like a charm. If you dont like the sponge idea, buy the extra media inserts, they're cheap and hold a fair amount of media.
As far as algae, doesn't look bad to me. 'Corse, I like algae. If it bothers you, turn the lights off sooner or on later.