Waterdrop AP431 Cartridge, Replacement for Aqua-Pure AP431 Hot Water Scale Inhibitor for AP430SS, Pack of 3

I use these on my tankless water heater. They work great and are easy to clean change. Reduces the need to clean unit as often.

Very good water filters . Very easy to install.

This system works great with my tankless water heater.

Very easy to install once the fitting has been placed to accept the product.

Ordered AP431 and got WD-W65 it says replacement for AP431. Vendor should correct the description and pictures. Also the cartridge is not full, the beads will rattle around when shook up and down. It is the same as the one I replaced, it is also a WD-W65.I use this in the supply line to my motorhome and it does a good job of keeping the lime scale down. It will not remove calcium, lime, or hardness ions or copper, magnesium, lead or other metals, it just sequesters or contains them so they will not precipitate out and cause scale. I got this motorhome 3 years old and the shower valve has so much scale in it, it sounded like it had sand in it. I replaced the valve and added the AP431. No problems for the past 3 years.I just built a little stand for it with 2.5 inch PVC pipe so I can keep it upright as it is supposed to be.It shows in the pictures you can use it for the whole house.I do have one question and that is how safe is it to drink and bathe in water that has polyphospates in it to sequester all the hardness minerals and what does it do in the body. I have asked and not gotten any concrete answers.