We touch on these topics in our FAQ, but our response in regard to chemical filtration is that you should continue using poly filters and carbon, but you can experiment with removing the carbon as the quality of the water improves. All biological and mechanical filtration should be kept the same, and you can still run a protein skimmer. Some have noticed an increase of build up on their filter socks and other media initially so you may need to keep an eye on excess build up and skimmer production. Check out this video from James Conrey regarding his filter sock.