my sand tank has not had a substrate change in over four years. the longest i have had a dirt tank last was 6 years, without dosing of any kind. the dirt was chicken manure, aragonite, a little clay, and old carbon. it was capped with sand. at startup, it was an algae nightmare for a month or two. after i got that under control with plants and an odd photoperiod, i had no complaints with it.
currently i have a cow manure, clay, and aragonite tank. no algae complaints so far, as long as i keep CO2 on it. its been the same substrate for about ten months, but had to be torn down and set up again because i moved four months ago.