In a tank that has been setup (150g) for over 9+ years: underfertilizing does not lead to algae outbreaks. I have had almost NO algae ever since it was set up and then only spot algae right below the lighting. Water changes are at best 2x/yr... 20-50%.
As far as I can tell...(over 40+ yrs) algae outbreaks are caused more by water changes than anything else. Especially if the tap water contains nitrates or phosphates from farm runoff.
