The use of pre-filters is important in prolonging the life of the (expensive) high pressure pump in your watermaker. Regular replacement of pre-filters is recommended. See your manual for specifics. Pre-Filter Housing Wrench makes opening the filter housing much easier. Works on the US Watermaker pre-filter housing, part number UWM 10230 - see related products below.
This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm.
www.P65Warnings.ca.gov