Pentair Pentek EP-20BB Big Blue Carbon Water Filter, 20-Inch, Whole House Carbon Block Replacement Cartridge with Bonded Powdered Activated Carbon (PAC) Filter, 20" x 4.5", 5

These filters were quite similar to the ones installed by Culligan. Quality seems great, it’s easy to install yourself, and the water flow issue was resolved by replacing old filter by this filter brand.

Exactly what you need! Fits perfectly, high quality filter.

I get municipal drinking water with 1-2ppm of of chlorine (as much as a public pool) and 22 grains of hardness (more than 2x what's considered "extremely hard"). When I had a water softener installed in my house, I also had a Pentek 20" Big Blue Housing installed before softener. I wanted the carbon filter for a few reasons: 1) Keep chlorine out of the shower and bath, out of my family's lungs and off of our skin 2) Keep chlorine out of the washing machine where it bleaches our clothing 3) Protect the resin in the water softener, which should double it's life 4) Protect the plumbing (PEX pipes, rubber in fixtures, etc...) from chlorine 5) Remove the small amount of sediment that is in the city water which collects in valves and fixtures I previously used the Pentek RFC20-BB Radial-Flow Granular Activated Carbon Cartridge . In comparison, this filter is less expensive, has a finer sediment filter (5 micron vs. 25 micron) and it's rated for up to 180F. Also, carbon block filters don't have the same channeling issues as GAC filters, which become less effective at higher flow rates. However, compared to the RFC20-BB this filter can't handle as much water (only 40,000 Gal. vs. 70,000 Gal.) and has a bigger pressure drop (5.5 psi @ 5 gpm vs. 0.9 psi @ 4 gpm). Neither of those were a big concern for me. We use less than 1,000 gal/week so the capacity easily exceeds the 6 month replacement cycle. As for water pressure, I get a solid 60+ psi coming into my house and even a 10 psi drop is not noticeable. If you already have pressure issues, get RFC20 instead.

Our water is tested super clean, this contributes to that goal.

Takes the chlorine smell out of city water.

I built out my water filter with gauges between each big blue. I don't have any experience with other carbon filters yet, but I can tell you that the pressure dropped from 65 psi on the inlet side to 25 psi on the outlet. You can still take a quality shower at 25 psi, but I will be experimenting with a different carbon filter when I replace this one. I haven't sent off any samples because I receive "safe" water from the water company. Water quality and taste have definitely improved, so I know it's doing its job. I'll update if anything changes or I do any sampling.

My go to filters for my in house water system, run in just before the softener system.

THESE ARE GOOD FILTERS AT A GOOD PRICE. I BOUGHT MINE AT AMAZON.COM FOR ABOUT $20.00 EACH. MY WATER IS CLEAR AND ODOR FREE. WHEN THEY SAY CARBON BLOCK THEY MEAN CARBON BLOCK - THE FILTER IS ONE SOLID PIECE OF CARBON. ONE BORKE IN SHIPMENT. I STILL USED IT. I PUT THE 2 PIECES BACK TOGHETER. WHEN THE FILTER HOUSING SCREWS ON IT TIGHTENED UP ON THE 2 PIECES AND HELD THEN IN PLACE QUITE WELL. [ABOUT 3." BROKE OFF ONE END.] THERE IS A FINE MESH ARROUND THE OUTSIDE WHICH TAKES OUT THE PARTICALE AND MAKES THE CARBON LAST LONGER. THE CARBON TAKES OUT THE TASTE AND ODORS. I HAVE WELL WATER WHICH IS PRETTY CLEAN TO START WITH BUT I WANTED THE ADDED INSURANCE OF THE CARBON FILTER. I HAVE IT IN A WHOLE HOUSE FILTER HOUSING IN THE BASEMENT. I PLAN ON CHANGING IT ONCE A YEAR OR WHEN THE PRESSURE DROP ACROSS THE FILTER INCREASES ABOUT 6 TO 8 PSI. I HAVE A PRESSURE GAGE BEFORE AND AFTER THE FILTER SO I CAN SEE WHEN THE PRESSURE DROP STARTS TO INCREASE. I CHECK THE PRESURE WITH ONE FAUCET [THE KITCHEN FAUCET] WIDE OPEN.