Why Is My Pool Green? (And How to Fix It Fast)

You walk outside, look at your pool — and it's green. Not a little green. Green green. Here's what happened, and what to do next.

What causes a green pool?

Green water means one thing: algae. And algae doesn't wait.

It usually takes hold when one of three things goes wrong:

• Chlorine drops too low (happens fast in Texas heat)

• Circulation stops or slows

• A storm or heavy debris throws off your chemistry

What NOT to do

Don't dump in extra chlorine and hope for the best. Shocking a pool without balancing pH first is one of the most common mistakes — and it makes the problem worse.

What actually works

1. Test your water first — pH, chlorine, alkalinity

2. Adjust pH to 7.2–7.4 before anything else

3. Shock the pool in the evening, after sunset (sunlight destroys chlorine fast)

4. Brush walls, floor, and steps — algae clings

5. Run your filter 24/7 until the water clears

6. Repeat chemistry check in 24 hours

Mild cases clear in 2–3 days. Heavy algae — the kind where you can't see the bottom — needs professional treatment. Our Green-to-Clean service typically takes 3–5 visits over one week and gets pools back to swim-ready.

Texas tip

Warm nights mean algae doesn't stop growing after sunset. The season here is longer than anywhere else — which means your pool needs consistent chemistry year-round, not just in summer.

Got a green pool right now? Contact us for a same-day Green-to-Clean quote: 469-888-1277