None. Micron filter put into service once every week after a water change to clear up any floating debris.
Dave Gomberg's CO2 system injected into a Barr CO2 reactor at a rate of 1-1/2 bubbles/sec.
Daily fertilization regime-
0.5 ml of Flourish,
5 ml of Potassium sulfate,
0.25 ml of Flourish Iron,
1 ml of Potassium nitrate,
7.5 ml of Flourish Trace added twice a week (due to my almost RO like water)