What is an Algae Scrubber? It is a device you build yourself which grows algae outside of your tank, so that the algae won't grow inside your tank. Algae is the main filter for the oceans and lakes, and algae makes most of the food there too. Algae WILL find a way to grow. So instead of fighting it, just let it grow naturally. In doing so, the algae will absorb ammonia, ammonium, inorganic nitrate, inorganic phosphate, nitrite, metals (including copper), and CO2. The algae will raise pH, and add oxygen, carbohydrates, vitamins, proteins, enzymes, lipids, amino acids, and last but not least (if saltwater) baby copepods to the water. In other words, the algae will do exactly what they do in oceans and lakes. And yes, this means they work in both fresh and salt water. Google "primary production" or "microbial loop" to learn more.
Another natural way to clean water is air injection which allows many benefits like particulate matter binding, better light penetration, helps corals remove waste, and raises oxygen levels.
Large macro algae refugium is another option for helping both water cleaning and natural aquarium snack maker
There is a ATS forum which should have some good reading for you and maybe change your mind about using GFO and other unnatural means. I would still use a butt kickN skimmer just not running 24/7.