You still should do water changes to help maintain the levels of all the other trace elements in your tank. Neglecting your filter pads/socks, skimmers, and just general weekly cleanings for a reef tank is a recipe for disaster. I don't want this to come off mean, but in this and many things people have a tendency to look for this magic solution that solves everything for them. But the problem is that there is no such thing as magic and keeping a reef tank is all about patience and work.
how often should i change everything n my sump i have filter floss, live rock n chemi pure elite as my biological plus i have carbon n a filter bag n my phosban reactor