A green pool is almost always algae. In North Texas it can take hold in a day or two once the chlorine runs low, especially in summer heat or after a storm. It looks alarming, but it can be cleared, and with the right care it stays clear.
Why Pools Turn Green
- Low chlorine. Hot sun, heavy use and rain all use chlorine up faster than normal.
- Poor circulation. A dirty filter, full baskets or a pump that doesn't run long enough leaves still water where algae grows.
- Debris. Leaves, pollen and dirt from storms feed algae.
- Water that is out of balance. When the chemistry is off, chlorine does much less work, even when there is plenty of it in the water.
Why It Keeps Coming Back
Pouring in shock from the store often turns the water blue for a few days, and then the green returns. That is because killing the algae is only part of the job. The dead algae still has to be filtered out, the filter has to be cleaned so it can keep working, and whatever let the algae grow in the first place is still there.
A pool that goes green more than once usually has an underlying cause: a filter that needs cleaning or new media, a pump that isn't moving enough water, or water chemistry that has drifted well out of range.
What a Professional Cleanup Involves
We start by testing the full water chemistry, not only chlorine, and checking that the pump and filter are doing their job. Then we treat the water, brush the whole pool, and clean the filter as many times as it takes to remove the dead algae. If a piece of equipment is the reason the pool turned, we show you what we found.
Most green pools clear within several days. Badly neglected pools take longer, and we tell you what to expect before we begin.
Is It Safe to Swim?
No. Stay out of a green pool. Algae makes surfaces slippery, the water may hold bacteria, and if you can't see the bottom you can't see a swimmer in trouble. Wait until the water is clear to the deep end.
Signs You Need More Than a Cleanup
- The pool turns green again within a week or two.
- Black or dark spots on the plaster that don't brush off.
- The filter pressure climbs quickly, or the pump struggles.
- Stains left behind after the water clears.
How to Keep It from Coming Back
Algae is far easier to prevent than to remove. During swimming season in DFW, weekly service keeps the chlorine, chemistry, filter and baskets where they should be, so the pool never gets the chance to turn.
Want us to take a look?
Talk to the owner directly. Consultations are free anywhere in Dallas–Fort Worth.