Review on Filtrete Standard Capacity Grooved Whole House Water Filters - Basic Filtration (2 Pack, Lasts 3 Months) by Tara Farmer

I don't know why people call these filters "charcoal". That's definitely not true. These are the main sediment filters. They are not even certified to the main production water quality standard 42. They are only certified to Material Standard 42. This means that the NSF certification team only confirmed that the filter materials should do the job of removing some buildup and odors, but the product hasn't actually been tested to make sure it actually does that! They won't remove chemicals, cysts (common microscopic protozoa that can make you sick), lead, or other dangerous chemicals (like haloacetic acid and worse). Standard 53 is next, and if certified to "Manufacturing Standard 53" it will remove some of the chemicals/protozoa just mentioned. NSF/ASI certification for water filters. I see people making all sorts of mistakes and assumptions about home water filters. People are very misinformed about this and also have issues with micron ratings. The smaller the number of microns, the smaller the particles or molecules they carry with them. Almost all chemicals are smaller than 1 micron, unless they're "coagulated" into particles that wouldn't be present in your regular household water. For this you need special activated carbon filters and reverse osmosis filters. Most of these filters are 5 microns in size; You can choose 30, 10 or 5 microns for this product. Always select 5 if the water pressure is OK. Less than 5 may require higher water pressure to push water through and if you don't have it your water (pressure) will fall out of the faucets and be uncomfortable or useless.