How many hours of lighting do you run on your tank? Can reduce the hours of white light if you want. Do you have direct sunlight on your tank? Have you checked your tank parameters? Don't assume since you're running chemicals, it's sufficient.
And actually, are you expecting no algae, no need to clean tank walls? lol I think this is a maintenance issue, everyone has to clean their tank walls every few days or algae will start to grow la. Part of the husbandry.
No, this is not like your normal tubes. If you wait until the ends of the tubes have black lines, your corals prob would have been light starved for a long time!