Hydronix HX-UDF-10C100E Softening Filter Cartridge with High Quality Nsf Certified Cation Resin 2.5" x 10", White

Construction of filter looks solid and is easy to install. But it doesn't do what's intended. Resin filters are supposed to attach to minerals in the water removing them. I have very hard water but it's very low in iron. I purchased this to fill humidifiers hoping the wicking filters would last longer. I attached a 1/4" tube to the filter housing to regulate the water flow and calculated it at just under 1GPM (well within spec for the filter). Even when the filter was fresh out of the package I was only removing 5% of the dissolved solids from my water.

Bought this filter hoping to reduce dissolved calcium and magnesium and thereby make my water softer. After several days I could not tell a difference on my skin so I decided to use a water hardness test kit which measures 0-425 ppm, comparing water run through the filter (inside house) vs water direct from the spigot at my well. The test strips were identical. I don't think this product does anything to reduce hardness.