The Same Mineral That Clogged a Machine in Space Is Building Up in Your Washer

It's one of the most common laundry complaints there is: clothes come out of the washer clean, but they don't smell clean.

Most people figure it's normal. That's just how towels smell after a while, right?

Then they start wondering if it's something they're doing:

So they change their routine. They switch detergents. They rewash the load.

And it comes out smelling exactly the same.

But the explanation turns up somewhere few people would think to look:

The short answer is that the smell isn't coming from the clothes. It's coming from inside the machine.

This might be a bit disgusting, so brace yourself:

The space station recycles the crew's urine back into drinking water, using a machine called the Urine Processor Assembly.

Like a washer, it runs the same kind of water through the same machine, over and over.

Soon after it started running, it failed. NASA's own report describes it in one flat line:

"A failure of the UPA due to the accumulation of solids in the Distillation Assembly."

In plain English: minerals built up inside the machine until it choked.

Astronauts lose calcium from their bones in low gravity, and that calcium ends up in their urine.

So every time an astronaut pees, the machine goes to work turning that urine back into clean water. And every time, the calcium leaves a thin layer of chalk behind.

Then another. Then another. Layer on layer, until the passages were packed solid.

That's how the machine broke down.

And it was buried deep inside the machine, where no hand or brush could ever reach.

Sound familiar? Your washer has spots just like that. More on those in a minute.

So NASA didn't try to scrub it out. They looked at the chemistry instead, and found something surprising.

It turned out the acid they'd been using to treat the urine contained sulfate. And calcium sticks to sulfate like glue, hardening into a chalky crust.

The treatment was feeding the buildup.

So engineers switched to a pretreatment based on "phosphoric acid," which has no sulfate in it. With nothing to lock onto, the calcium stays dissolved and drains out with the water instead of setting on the walls.

And here's the clever part.

NASA doesn't wait for the machine to clog and then clean it. A small dose goes in every single time the toilet is flushed, so the mineral never gets a chance to build up.

Your washer has more in common with that machine on the space station than you'd think. And it comes down to water.

After federal efficiency standards tightened in the 2000s, washers had to do the same job on a fraction of the water.

Manufacturers sealed the doors tighter and dropped the fill levels.

That's good for your water bill. But to get clothes clean with that little water, many high-efficiency washers reuse it during the wash. With less fresh water carrying minerals and residue away, buildup collects in the hidden parts of your machine.

Round and round goes the same water, and the hidden parts never fully dry.

That water carries dissolved chalk from the ground, whether it comes from a city line or a well (and well water carries more).

Each time it dries inside your washer, a little chalk stays behind, like the white ring in a pot after you boil water.

It's the same thing that happens on teeth. Smooth enamel is hard for anything to cling to. But once tartar builds up, plaque grabs onto it, and that's what causes bad breath. Mouthwash covers it for an hour. Brushing helps. But the smell keeps coming back until the tartar comes off.

Your washer works the same way. The chalk is the tartar. The film is the plaque. And the smell won't go away until the chalk does.

The drum you load clothes into is only part of the washer.

Around it sits an outer tub that holds the water. Below it is a sump, where water pools before it pumps out. Behind the detergent drawer is a channel every scoop of soap runs through. And on a front loader, the rubber ring at the door has a fold that holds water like a gutter.

Water goes through all of it, every cycle. A hand or a cloth reaches almost none of it.

Two more quick tests:

Washer makers have faced lawsuits over musty front loaders for years.

In one federal case, the appeals court's opinion described evidence that the manufacturer knew its new cleaning cycle "would not remove all residue deposits."

A jury later found the manufacturer not liable, so this isn't a story about wrongdoing. It's a story about expectations: even the people who designed that cleaning cycle didn't expect it to remove everything.

The home remedies run into the same wall. Most are made to go after the film, or to cover the smell. None of them is made to dissolve the chalk underneath.

When the problem is mineral, the answer is an acid. That's the principle NASA landed on.

A washer can't use what NASA used. Their pretreatment was built to stop crust forming in a machine in orbit, not to clear years of it from a laundry room.

But the principle carries over.

And hard-water homes tend to notice the biggest change, because more minerals going in means more chalk on the walls.

One honest limit: no tablet reaches into the fold of the door ring. Pull it back and wipe it out once a week.

Remember the space station. NASA doesn't wait for the machine to clog. It treats every flush, so the mineral never gets a head start.

Your washer gets its own drip of chalk with every load.

That's why X-All is made to be used after every load. Drop a tablet into the empty drum once the clothes come out, and the new layer clears while it's still thin, before it gives the film anything to grip.

And one that's worth reading closely:

She's right. Buildup that went on in layers over a decade comes off in layers, which is why the first few weeks matter most.

Add up what a musty washer quietly costs a household: scent beads, extra detergent, bleach, jugs of vinegar, all bought again every few weeks.

Then there's the bigger number many people start looking at: a new washer, often $800 or more.

P.S. If towels smell fine out of the dryer but musty out of the closet, the problem isn't the laundry. It's the layer inside the machine. And you can dissolve it with X-All, which comes with a 30-day guarantee.