I didn’t know dishwashers had filters. For three years. Three years of glasses coming out with cloudy spots and a faint locker-room smell every time I opened the door.

I assumed the dishwasher was just getting old. My apartment maintenance guy pulled out the filter during a routine check, held it up with two fingers like it was radioactive, and asked if I’d ever cleaned it. I said, “There’s a filter?”

Where your filter lives

Pull out the bottom rack. Look at the floor of the dishwasher, under the spray arm. There’s a cylindrical thing — usually with a twist-off top or a couple of clips. That’s the filter.

Every dishwasher made after 2010 has one. If yours doesn’t seem to have one, check the manual. Some are hidden under the spray arm itself.

What you’re going to find down there

I’ll warn you: it’s gross. Bits of decomposed food. A slimy film. Maybe a piece of onion skin from that time you didn’t rinse the plates. The smell is… distinct. You’ll want gloves.

The filter catches food particles so they don’t recirculate onto your supposedly clean dishes. When the filter is full, it backs up. The water gets dirty. Your glasses get cloudy. Your dishwasher starts smelling.

The cleaning method

1. Twist out the filter. Most unscrew counterclockwise.
2. Rinse it under hot running water. Use a soft brush — an old toothbrush works perfectly — to scrub between the mesh screens.
3. If it’s really bad, soak it in warm water with dish soap for ten minutes first.
4. While the filter is out, wipe down the filter housing with a paper towel. Gunk collects in there too.
5. Replace the filter. Twist it back until it clicks or locks.

How often to do this

Manufacturers say once a month. Realistically, if you rinse dishes before loading, every two to three months is fine. If you don’t rinse, do it monthly.

I set a recurring reminder on my phone. First of the month: check dishwasher filter. Took me three years to learn this lesson — you can learn it in five minutes.

The deep clean bonus round

Once the filter is clean, run an empty cycle with a cup of white vinegar placed upright on the top rack. This descales the spray arms and the interior. If your glasses have that white film, this will fix it.

My dishwasher smells like nothing now. My glasses come out clear. Three years of cloudiness solved by a ten-minute filter-scrubbing session.