Pool Algae Doesn’t Care That You Just Opened

You pulled the cover off, tossed in some shock, and patted yourself on the back. Pool season is back. But here’s the thing: algae didn’t get the memo that you weren’t ready. It’s been waiting. Quiet. Opportunistic. And now that your water’s warming up and chlorine’s still finding its way around, it’s the perfect time for it to strike.

Don’t take it personally. Algae isn’t targeting you. It just happens to thrive in the exact moment you let your guard down. And opening week? That’s prime time.

Algae comes in flavors. None of them are good.

• Green algae: The most common. It floats. It spreads fast. And if your chlorine isn’t right, it’ll own your pool in a day.
• Mustard algae: Yellow, clingy, and usually hiding in shady corners like it pays rent there. Tougher to kill, and often mistaken for pollen.
• Black algae: The worst. Think of it like mold with attitude. It roots deep into plaster and laughs at your half-hearted scrubbing.

The trap: thinking your water looks fine

Early-season water is tricky. It might look clear, but that doesn’t mean it’s clean. Algae doesn’t always show up in dramatic green clouds. Sometimes it starts as a slick film, or a patchy hue in the corners. You ignore it, and by next week, you’re swimming in salad.

What to do now (before it blooms)

• Brush your pool. Everywhere. Even if it looks clean. You’re knocking loose the stuff that’s about to become a problem.
• Test and adjust your chlorine. Opening week chlorine often isn’t enough. Get it up to shock level and hold it there for a solid day.
• Run your pump around the clock. Circulation is everything. Dead spots = algae playgrounds.
• Backwash or clean your filter. If your filter’s clogged, it can’t fight anything. Don’t skip this.

If it’s already too late…

Go nuclear. Triple shock. Brush twice a day. Consider a specialty algaecide if things are bad. And don’t take shortcuts. Algae comes back stronger if you only half-kill it.

This stuff isn’t cute. It’s not a rite of passage. It’s a nuisance that ruins good weather and makes you hate your own pool. Handle it now, and don’t assume your pool is safe just because the water looks blue. Algae knows better.

You opened your pool. Nice. Now keep it clean like you mean it.