Hi Dan,
A protein skimmer will not export nutrients, if it did
nobody would have an algae problem, lights are not the cause of algae
although they can contribute to the growth, algae is caused by excess
neutriants, caused by incorrect filtration, or from the water supply,
or overfeeding. The best nutrient control, after you have eliminated
the main source is a deep sand bed 4" to 6" in the tank or the
refugium.
regards,
unclenorm.