Aftermarket "431 Cartridges" vs 3M

[Kira]

3M markets an inline cartridge which imparts an anti-scaling chemical to your hot water.
This cartridge mounts on the cold water line to the hot water heater.
It's called Aqua Pure and the model is AP-431.
A family friend installed this when he installed our water heater. Our water is exceptionally hard.

A look at Amazon revealed several aftermarket suppliers.
Their names include, Water Drop, Aqua Quest and KleenWater.

I don't want the false economy of cheap products. And while I have regard for many of 3M's products, I find them quite expensive at $45 each.
Aftermarket brands are $12 to $16 each.
Without a glass shower enclosure, I've no way to observe, let alone compare, any of these cartridge's effectiveness.

If anyone has any experience, I'd love to hear it.

 

[JohnnyG]

My only experience with aftermarket water filters was not good. Specifically, fridge filters, which I always take apart to check for anything odd once they are done.
The original Frigidaire version had about 9 inches of solid carbon filter material and was well sealed at both ends. The aftermarket version, which was half the cost easy and was the same external length, so it looked identicle. However, it only had about 5" of filter material inside, which looked a little more porous, and didn't have great sealing surface to ensure that ALL the water was filtered.
So, yeah, they are usually cheap for a reason.

 

[Tdbo]

There is only one way to truly find out.
Try one of the brands that you mention. Go for the highest rated.
If it proves not to be up to the task, go back to the 3M.