BPS-120M The Biological Pit Enhancement System enables you to inject air, microbes and nutrients into water stored in pits where oil collects and gathers. The BPS Series will improve the quality of the water by decreasing the amount of oils while adding oxygen. The Biological Pit Enhancement System consists of: · 2 aeration pumps - linear pumps are used to infuse air into water collection pits · 2 peristaltic pumps - used to inject bacteria and nutrients if so desired Features include: · 115V or 230V single phase settings (consult dealer for more information) · 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.