I moved my 200 litre reef tank 2 months ago, due to building work. I also added another T8 white light (2 in total now) which work together with one blue light. Slowly but surely a slimmy brown maroon algae has been growing on glass and rocks. It comes off easily enough but is an aesthetic nusenece. What could be causing this algae growth? I have little in my tank at present (6 fish in total) and haven't added anything new either. I do 10% water changes weekly and salinity sits at 1.023 according to reefractometer. What should I test/do/eliminate to try get rid of algae?