Bests & Worsts Reviews from Amazon

This filter seemed like a good deal. Who can resist a "5-year filter"? However, if you stop and read the performance data, this filter doesn't work as well as other filters. This information is not included in the Amazon description but you will find the Performance Data sheet when you get the product or when you request it from Watts. Here's what the Watts Premier 5-yr in-line filter (see photo) Performance Data sheet says: ------------------------------average influent----------------average effluent-----------------------% reduction aesthetic chlorine---------1.94 mg/L------------------------0.44 mg/L---------------------------------77% This means the initial concentration of chlorine in the water they tested was 1.94 mg/L. The final chlorine concentration, after passing through the filter, was 0.44 mg/L. Chlorine was, therefore, reduced by 77%. This filter has only been tested, following NSF standard 42, for chlorine reduction. It is not NSF-certified. It doesn't show the test results for reduction of class 1 or class 5 particulates or for any other parameter. I do not know where the "bacteriostatic" description in the Amazon listing came from since there is nothing in the Watts leaflet that indicates the filter is bacteriostatic. My primary reason for using a water filter is to reduce chlorine and class 1 (0.5 to 1 micron) particles. I will compare the Watts filter with the Filtrete 3US-PS01/3US-PF01 (see photos of the Performance Data sheets of these two water filters). ------------------------------------------Watts filter-------Filtrete filter chlorine reduction-----------------------77%-------------95.7% Class 1 particulate reduction ------no data-----------99.8% cysts reduction-------------------------no data----------99.99% The Watts filter reduces chlorine by only 77% while Filtrete 3US-PS01/3US-PF01 reduces chlorine by 95.7%. The Watts filter performance data sheet did not include their data for particulate reduction which indicates that their filter's performance did not meet NSF reduction requirements for particulates. Filtrete 3US-PS01/3US-PF01 reduces class 1 particulates by 99.8% and cysts by 99.99%. NSF reductions requirements is >/= 85% for class 1 particulates and >/= 99.95% for cysts. Cysts refer to oocysts of Cryptosporidium parvum. C. parvum is a protozoa. When ingested, they cause acute, watery, nonbloody diarrhea. I'm not particularly interested in the cyst filtering feature since our city water doesn't have that problem. Like I said, I'm mainly interested in chlorine and particulate reduction. The CDC, however, states that Cryptosporidium is a leading cause of waterborne human disease in the USA. [...]. So, let the water quality in your area be your guide in determining what kind of filter you need. Now, let's compare the rated capacity and service flow. This is information that you will see on the product packaging and the information sheet inside the packaging: --------------------------------Watts filter-----------------Filtrete filter rated capacity-----------20,000 gallons-------------2,000 gallons rated service flow--------0.5 gpm*---------------------1.5 gpm *gpm = gallons per minute While the Watts filter does filter a lot more water, I prefer the Filtrete 3US-PS01/3US-PF01 because of the higher chlorine reduction and particulate filtering.