maintain Fw and marine system with a strong emphasis on balanced, stabilized system that as much as possible are self substaning.
have maintained FW systems for up to 9 years with descendants from original fish and marine aquariums for up to 8 years.
With no water changes, untreated tap water, inexpensive lighting by first starting the tank with live plants (FW) or macro algae( marine)
see:
http://www.tropicalfishkeeping.com/advanced-freshwater-discussion/beaslbob-build-295530/