I had a water softener installed last year and included a 10 inch big blue style whole house water filter. I asked for it because I wanted to reduce chlorine from my city water (good quality). I dislike red eye from chlorine while in the shower. Water from the faucet also tastes better now. Laundry also looks a little brighter, although that might also be affected by the water softener.

It works well and I just replaced my filter for the first time. It came with a 20 micron activated charcoal style (GAC-BB). I replaced it with a Liquitec 5 micron solid style. The replacement filter works well although I see that it reduced water pressure a little over the GAC-BB.

While shopping for filters I discovered as much advertising hype as I did good information.

For the needs I described above, are there any fact based opinions on what to look for in a filter replacement? Also, about replacement frequency, I use about 2000 gallons a month. When the mfgr or distributor says 12,000 gallons or 3 months before replacement, what are they talking about? What is a reasonable life expectancy for a 4.5" x 10" cartridge?