I have had mine running for a week and no traces of algae (freshwater). I have high nitrites and nitrates as it is a test tank with goldfish. I don't think it needs to fully cycle before growing algae. I used fiberglass screen for the scrubber. It is the same screen that goes on the outside of windows to keep bugs out while leaving the window open. I sand papered the screen a little, but not much as it has plenty of places for algae to grow. Do you think fiberglass is too slippery for the algae?