[chocophile]

We also draw water from the lake, but instead of a cartridge filter we have a resin tank filled with garnet. It automatically backwashes once a week to the outside. We don't do much to maintain the resin tank. I guess you could replace the garnet periodically, but we never have (10+ years).

The backwash controller can measure gallons of use or time (days between backwashes). The gallon meter broke a few years ago so we just do time.

During the backwash, a small secondary tank filled with bleach and water supplies a solution to sanitize the resin tank. I suspect that reduces odor.

The resin tank is about 4' tall and 8" in diameter, filled about 3/4 full with garnet.

After the resin filter tank, we have a UV sterilizer, then a point-of-use carbon filter at the kitchen sink.

We did a water test a couple of years ago, and the results were fine.

It's conceivable that the garnet filter isn't doing 5- or 10-microns (whatever the UV sterilizer is rated for) but it all seems to work well.

So, you might check into the addition of a resin filter tank upstream of your cartridge filter. You'd have to get a plumber to install it.