Whatr size aerator pump is needed for a 500 gallon aerobic system?

Option 1 - check with the local health department or wherever septic plans are filed locally and see what your system was designed to have - the system design should be on file there from when it was permitted/approved.

Option 2 - hire a septic design engineer.

Option 1 should be free. Option 2 costs money. Pulling a number out of the hat on the internet is not a good option.

80 Liters of air per minute is the standard size for a 500 gpd system. Some systems use a rotary vane type aerator as well but these are less common do to cost and because they are a little louder. The best aerators on the market are the Fuji Mac 80r2 3 year warranty, Hiblow HP-80 2 year warranty and used by most manufacturers of aerobic septic systems. Also the Secoh JDK-80 other great unit. Some 500 gpd systems use a 40 liter a minute pump but it’s rare and questionable when you have 80 percent of the systems using 80s.

Most homes are under 2500 sqft so they use a 500-600 gpd system.Most systems of this size use a 80 liter a min pump such as a Hiblow Hp80, Secoh EL-80,Fuji Mac80R2,a Gast AT05 will aslo work. The number at the end of most septic air pumps is the literes of air per min. As the systems get larger the pump size increases as more dissolved oxygen is needed to treat the waste water.