Inline Filters

Inline Carbon Water Filters: The Post Carbon Filter Stage

An inline carbon water filter is the last stage most drinking water systems run before the faucet. Granular activated carbon (GAC) reduces the chlorine, chloramine, and odor compounds that make water taste flat or chemical. In under-sink reverse osmosis systems, this post-carbon filter also polishes water that has been sitting in the storage tank, so the first glass tastes as clean as the last.

AFW carries two in-line carbon filter options: the Hydronix Inline Carbon Taste & Odor Post Filter - 2-inch x 10-inch and the Inline 3/8-inch Carbon Taste & Odor Post Filter - 2-inch x 10-inch.

Choosing 1/4" or 3/8" Quick-Connect Fittings

Match the fitting to the tubing already on your system. Most residential RO systems and refrigerator lines run 1/4" tubing, which suits the Hydronix post filter. Systems plumbed with 3/8" tubing take the Inline 3/8-inch Carbon Taste & Odor Post Filter, so you avoid reducers and the flow loss they bring.

Where a Post Carbon Water Filter Sits in an RO System

Water passes the RO membrane, collects in the storage tank, then runs through the post carbon water filter on its way to the faucet. That position is why the post filter shapes what you actually taste. The 2-inch x 10-inch size mounts with standard filter clips.

Inline Arsenic Water Filter

Arsenic has no taste, color, or smell, so it needs its own stage. The Inline AdEdge AD2X10C Filter, which reduces arsenic (V) and (III), is packed with 100% Bayoxide® E33 media and is rated to reduce both forms of arsenic without a separate oxidation step. Integrated 1/4" quick-connect fittings let it join an existing drinking water line, and the 2" x 10" body fits common filter clips.

This inline arsenic water filter treats a single drinking water tap. For arsenic at every tap in the home, see AFW's whole house arsenic filters. Arsenic level, arsenic form, and the rest of your water chemistry all affect results, so test before choosing.

Specialty Inline Stages: DI, pH and Alkaline

Not every inline stage is about reducing contaminants. These three change the character of water after reverse osmosis, which matters for reef tanks, acidic RO water, and taste preference.

Deionization

The Omnipure Inline DI Filter - 2.5-inch x 10-inch (K5555-JJ) uses deionization resin to take RO water down to very low TDS. It's the stage that turns drinking-quality RO water into the near-pure water used for reef tanks, sensitive aquariums, and spot-free rinsing, and it's built into AFW's aquarium RO/DI systems.

pH Re-mineralization

The Omnipure Inline pH Re-mineralization Filter - 2-inch x 10-inch (K2548-JJ) uses calcite media to neutralize acidic water and raise pH toward a neutral 7.0. RO water can leave the membrane slightly acidic, so this is a common add-on for owners who want a smoother taste.

Alkaline

For water above neutral, AFW stocks the Inline Alkaline Filter - Increases pH & Alkalinity, Adds Numerous Minerals, and Lowers ORP, and the Aptera Alkamag Inline Alkaline Filter - 2.5-inch x 12-inch, an 11-stage cartridge listed to raise pH to 8.0 or higher.

Inline Sediment Pre-Filter

The Hydronix Inline Sediment Filter 2-inch x 10-inch catches sand, sediment, and large particles before they reach carbon or a membrane. Placed first in line, it protects every stage downstream and helps them last.

How to Match an Inline Filter to Your System

Start with the problem you're solving, then where the filter sits, then the tubing size. Use this as a quick reference.