Features: 2 aeration pumps - linear pumps are used to infuse air into water collection pits · 2 peristaltic pumps - used to inject bacteria and nutrients · 2 aeration stick assemblies - prevents water from stagnating in pit systems · 115V single phase setting · Internal timers allow end user to control the amount and frequency of the liquid microbes and nutrient doses. The BPS Series can be set to inject bacteria every minute, every hour or every day, whatever the situation dictates