20 high nano Reef

I am new to salt water but not new to aquariums. I have a 55 gal discus ram tank and a 20 gal axolotle tank. What are your thoughts on establishing an ecosystem in the tank instead of constant water changes and alterations. I have not changes the water once in my discus tank. I figure if I get my plankton and copeopds established I could have a decent setup for reef. What are your thoughts.