WHKF-DWHBB Whirlpool Filter Housing with Pressure Relief Valve - Clear
Product Review (submitted on October 28, 2013):
I installed this filter when I installed my WATER SOFTENER. They recommended I install this ahead of the softener so it will work much better.
First installed and about one week after the install, it became dark orange color which means lots of ferrous was being removed. it was amazingly impressing that there was so much iron in the water, maybe from the long time worn pipeline...
I am currently changing the filter every 3 month... it says the regular period is 6 months..