iSpringFA15 10-inch Inline Quick Connect 3-Layer Alkaline Replacement Water Filter Cartridge with Mineral Balls, Calcite, and Corosex for Reverse Osmosis RO System, White

Really good filters from this brand / not altering the taste of water as from previous company which i used and gave me a lot of debris at the outer part of filter

Perfect but little on pricey side to other options.I wanted something to add to my 6 stage RO system which comes out at zero for my reef tanks. As I now live in a very hard water area with no reservoirs the water smells and is awful up this way.Added this to the side to which I divert the water for drinking. Comes out at around TDS 82 perfect and even better with a slice of fruit.

Be sure flush it for 5 mins before use. Added 20 TDS to final output and ph went from 6 to 7.5, for aquarists, GH is 5° and KH 8°.

Value of money

There are 2 types of connecting holes for this cartridge, thinner screw variety and a fatter 'easy-click' type. This is the latter, unfortunately my ispring unit was the former, so they are incompatible.Othwrwise a great system and the seller sent over spare parts a week later.

I've had my 5-stage iSpring for several years and have been pleased with the taste. While I think we're not meant rely on our drinking water to get our minerals, sometimes I get questions of concern from guests. Word to the wise: best not to even mention that your water filter is RO. Sometimes people think it's distilled water. Ugh. Anyway, I bought and attached this sixth alkaline stage and did a before and after taste test. The 'before' was just as good as ever. The 'after', now going through the filter, has a slight brightness to it which, while not a huge difference, is to my taste buds preferable.

Works with my 6 stage reverse osmosis watering system.

Good