The process of using turf algae to filter aquariums has been around for decades, but the contraptions were just too huge and expensive, and for some reason nobody thought to make a simple one in a nano hood. It's simple enough (and free) that you should try one on your system even if you have no intention of eliminating your skimmer, etc. The principal is very simple: You have a screen; light is aimed at the screen, and tank water is streamed over the screen. What happens is that algae starts growing on the screen, and this algae eats almost all the nitrate and phosphate in the water flowing over it (and so the algae in your tank will not have anything to eat!). However, the turf does NOT eat the food/pods/plankton in the water, so this food will stay in the water for the corals to eat. This is the OPPOSITE of a skimmer, which takes out the food/pods/plankton (so corals starve), but leaves in the nitrate and phosphate that you have to then get out using other means. What about fish waste that skimmers normally pull out? Well that's food too, for somebody! Only after waste decomposes completely into nitrate and phosphate is it no longer "food", and at that point the turf zaps it! After all, what do you think the green algae on your rocks and glass are eating? Food? No. Nitrate and phosphate!
