When dealing with water of unknown quality having a little insurance never hurts. We use the compact chemical removal filter (RM200) in all of our Outback OB-22FF and OB-22NF models. This filter maybe small in size but it is big on performance. The RM200 measures 2.5” x 6” with a ¾” male thread on the inlet side of the filter. The rated chemical contaminate removal capacity of this filter is over 1200 gallons.
See list of contaminates