NSA 100S and 100SX Replacement: The USA-100 Under Sink Filter

For years, the NSA 100S and NSA 100SX were go-to under sink water filters. Both models have been discontinued, so if yours is due for replacement, you can't simply order the same unit again. The good news: the made-in-USA USA-100 Under Sink Water Filter was built to replace them.

How the USA-100 compares

The USA-100 takes the place of your NSA 100S or 100SX and improves on the original design:

  • 5-stage filtration and purification with bacteriostatic GAC/KDF media
  • 25,000-gallon capacity
  • Bacteria protection for up to 36 months, so bacteria can't grow inside the filter
  • Improves taste, eliminates odors and removes color, and reduces hundreds of contaminants (see GAC key)
  • Hooks up to your existing water line and faucet with quick connect or compression fittings
  • 14" high x 5" diameter, sized to fit under the sink
  • Made in the U.S.A. with a 60-day full replacement and 1-year pro-rata warranty

How to replace your NSA 100S or 100SX

  1. Turn off the cold water supply valve under your sink.
  2. Disconnect your old NSA filter from the water line and faucet line.
  3. Connect the USA-100 inlet to the cold water line and the outlet to your faucet line, using the quick connect or compression fittings.
  4. Turn the water back on, check every connection for leaks, and run the faucet for a few minutes before drinking.

Need help? Call us at 888-672-3458 and we'll walk you through it.

When to replace it

Replace the USA-100 after 25,000 gallons or 36 months, whichever comes first. If the chlorine taste or smell comes back, that's another sign it's time. Read more in How often should you change your water filter?

Looking for a different NSA replacement?

Shop the USA-100 Under Sink Water Filter

*NSA is a trademark of its respective owner. USA Filtration is not affiliated with NSA.

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