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Watts reverse osmosis system with white filter housings, booster pump, storage tank and faucet

Reverse osmosis system

Watts 315 3-Stage RO Replacement Filters

This is a traditional, 3-stage reverse osmosis system for undersink use. Be sure to replace the carbon pre-filters at least once annually and the RO membrane every 2-3 years. These parts as well as the replacement tank and maintenance kits can be found below.

See the replacement schedule

Compatible parts

Everything that fits the Watts 315

Omnipure OMB934-5m 5-micron carbon block filter for standard 10-inch water filter housings
Omnipure
Omnipure OMB934-5m Carbon Block Filter 5 Micron 2.5" x 10"
(84)
$14.99
Reduces chlorine, taste and odor
NSF Certified performance
USA made compression molded
2.5" Drop-in carbon block element
AXEON TF - 1812 - 50 Reverse Osmosis Membrane 50 GPD 200359 200359 - ESP Water
AXEON
AXEON TF-1812-50 Reverse Osmosis Membrane 50 GPD 200359
(10)
$44.49
Thin Film Composite (TFC)

Replacement filter info

Your replacement schedule

Each stage of the Watts 315, the exact part that fits it, and when to change it.

  1. Stage 1: Carbon block filter

    Part OMB934-5m, Omnipure OMB934-5m Carbon Block Filter 5 Micron 2.5" x 10" $14.99

    Every 6–12 months

  2. Stage 2: RO membrane

    Part 200359, AXEON TF-1812-50 Reverse Osmosis Membrane 50 GPD 200359 $44.49

    Every 2 years

  3. Stage 3: Post carbon filter

    Part OMB934-5m, Omnipure OMB934-5m Carbon Block Filter 5 Micron 2.5" x 10" $14.99

    Every 6–12 months

Manuals & instructions

Manuals and guides

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