Already have a kit?

Refill 4-pack

4 more in-home microplastics tests. You get the parts a test uses up — the staining vials and the syringe filters. Everything else from your kit gets reused.

Free shipping · $7.00 a test

Don't have a kit yet? Start with the full kit — $75 →

The Water Test kit — the refill replaces the vials and filters

What's in the 4-pack

4× staining vials

Vial 1 (peroxide) + Vial 2 (Nile Red) for each run

4× syringe filters

Fresh membrane per test — no rinsing, no carry-over

Nothing you already own

Reuse the digital microscope, phone stand, and syringe

Why people grab a refill

  • Re-test the same filter a few months later
  • Check the water after replacing a filter cartridge
  • Test a second source like the fridge, pitcher, or bottled water
  • Cheaper per test than buying another full kit

New to the test? See how it works