That Yellow Gunk Nearly Ruined My Summer: How I Fought Mustard Algae in My Pool and Won (Thanks, Beatbot)

Every year, like clockwork, our pool becomes the heart of our summer. It’s the place we float with lemonade in hand, the stage for ridiculous cannonballs, and the cooling-off zone after mowing the lawn in 95-degree heat. But this summer… something was off. I started noticing these weird yellow stains around the edges. I figured it was pollen or maybe some dirt kicked in by the kids. I wasn’t too worried—at first. But then it got worse. The yellow patches thickened. They crept up the walls, hid in shady corners, and mocked my feeble attempts to scrub them away. Welcome to my personal horror story: mustard algae in the pool.

Let me back up a little. I’ve had this pool for years. I’m not a newbie. I know how to vacuum, balance chemicals, shock when needed—the basics. But this yellow stuff? It didn’t care. No matter how hard I brushed or how many chemicals I dumped in, it came back. Every. Time. It was like playing whack-a-mole with slime.

I started Googling like a maniac. That’s when I stumbled across the phrase that gave me chills: mustard algae.

Apparently, this isn’t your garden-variety algae. It’s clingy. Stubborn. Smarter than it has any right to be. It hides from chlorine, gets into pool toys, even survives in bathing suits. What?? How did I not know about this?

So began my full-on war.

The first thing I did was nuke the pool with chlorine. Triple shock. Bleach all the inflatables. I even bleached our swimsuits, which felt excessive, but desperate times, right?

I scrubbed the walls so hard I gave myself blisters. I ran the filter nonstop. For a few days, it worked. The pool looked clean, sparkly even. I thought I’d won.

Nope. A week later, the yellow stains were back, grinning at me like they’d never left. That was the breaking point. I was so close to just throwing a giant tarp over the whole thing and calling it “decorative pond art.”

But before I did anything dramatic, I stumbled across something that changed the game.

Late one night (okay, very late—I couldn’t sleep thinking about algae), I came across a forum where someone mentioned robotic pool cleaners. I’d heard of them before but always assumed they were overpriced gadgets that only rich people used.

But this one review stuck out. A guy said his Beatbot robot, part of the AquaSense 2 series, helped him finally beat mustard algae after months of fighting it. He said it did what he physically couldn’t: get into every crevice, every weird angle, every spot that his brush just couldn’t reach.

I was skeptical. I mean, could a robot really do what I couldn’t?

I bought it anyway. Because I was out of ideas.

Setting up the Beatbot was way easier than I expected. It practically introduced itself when I dropped it into the pool. Then it just… started cleaning. No drama, no weird instructions, just quiet, calculated movement.

I remember sitting there with my coffee the first morning watching this little machine zigzag methodically across the floor. It looked like a pool Roomba with attitude. And I liked it.

Within a week, things started shifting. The yellow tint started to fade. It wasn’t hiding in corners anymore. The Beatbot was relentless, getting into places I hadn’t even thought to check. And since it ran consistently, the algae never got a chance to regroup.

And the best part? I didn’t have to babysit it. It just did its thing. Every day. No complaints. Unlike me.

There’s this unexpected side effect to all this: I got my time back. I wasn’t constantly scrubbing and stressing. Instead, I started paying attention to the stuff I’d neglected—like keeping the chlorine and pH levels more consistent, and actually enjoying the pool instead of resenting it.

Even my kids got into it. They named the robot "Otto" (short for Autobot, obviously) and would race each other to see who could fish it out fastest when it finished its cycle. It turned a tedious chore into something kind of… fun?

Honestly, I felt like I’d been upgraded. Smarter cleaning, fewer headaches, more time doing what pools are actually for—like floating aimlessly with a drink in hand and absolutely no algae in sight.

It’s been nearly two months since the Beatbot joined our family, and the mustard algae? Gone. Not faded, not hidden, but truly gone. It’s not just the clean pool that gets me though—it’s what came with it.

The energy to plan pool parties again. The peace of mind to swim without worrying what’s growing beneath the surface. And the pure, unexpected joy of watching a little robot do its job like a tiny, silent champion.

I know it sounds dramatic to say a pool cleaner changed my summer, but honestly? It kinda did. So if you’re out there battling yellow gunk that refuses to die—maybe it’s time to stop scrubbing and start thinking smarter.

Otto and I will be over here, enjoying the water. You’re welcome to join us. Just rinse your suit first. We don’t want any stowaways.

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