Why Does Algae Keep Coming Back in My Pool?
Algae keeps coming back when something is keeping chlorine from doing its job. The most common cause in Bakersfield is stabilizer (cyanuric acid) that has built up too high from chlorine tablets, which makes chlorine weak even when the test looks fine. Other causes are stopping treatment too soon, a dirty filter, short pump run time, and not brushing. A water test that includes stabilizer and phosphates will show which one it is.
What are the usual causes?
- High stabilizer. Above about 80 to 100 ppm, chlorine is so shielded that algae outgrows it.
- Stopping too soon. The water looks clear, but some algae survives and regrows.
- Low or uneven chlorine. Chlorine that drops to zero for even a day in summer gives algae a start.
- A dirty filter or short pump time. Dead algae and debris stay in the water and feed the next bloom.
- Dead spots. Steps, corners, and the area behind ladders get little circulation.
- Phosphates. Dust, leaves, and fertilizer add food for algae.
- Contaminated gear. Brushes, toys, and swimsuits carry algae back in.
How do I break the cycle?
- Step 1: Get a full water test, including stabilizer and phosphates.
- Step 2: If stabilizer is over about 100 ppm, replace part of the water. No chemical removes it reliably.
- Step 3: Clear the algae completely. Hold chlorine at shock level until the water is clear and chlorine drops by 1 ppm or less overnight.
- Step 4: Clean the filter after the algae is gone.
- Step 5: Keep free chlorine matched to your stabilizer level every day. We will give you your target number.
- Step 6: Run the pump long enough to filter all the water at least once a day, 8 to 12 hours in summer.
- Step 7: Brush weekly, especially steps, corners, and shady walls.
- Step 8: If phosphates test high, ask us about a phosphate remover such as Orenda PR-10,000.
Why are Bakersfield pools prone to repeat algae?
The swim season is long, the water stays warm for months, and summer sun burns chlorine off fast. Tablets are convenient, but every tablet adds stabilizer, and after a few seasons many local pools carry far too much. Wind storms add dust and debris that feed algae. Many pool owners here use liquid chlorine for most of the season, or alternate, and check stabilizer every month or two.
When should I call for help?
Bring in a sample or call us if algae returns within two weeks of a full treatment, if stabilizer is over 100 ppm, or if the pool has turned too green to see the bottom. For pools that far gone, our Green to Clean service brings the pool back to clear, cleans the filter, and adds startup chemicals. Call (661) 664-9000 for a quote.
Will algaecide stop algae from coming back?
It helps as prevention, but it does not replace chlorine. If algae keeps returning, fix the chlorine, stabilizer, and filtration first.
Do phosphates cause algae?
Phosphates are food for algae, not the cause. A pool with good chlorine can carry some phosphates without trouble, but high levels make algae harder to control.
How do I know when the algae is really gone?
The water is clear, the walls are not slippery, and chlorine drops by 1 ppm or less between sunset and sunrise.
Does brushing really matter?
Yes. Brushing breaks up the film algae hides under and pushes it into the water where chlorine and the filter can reach it.
Don't cry, we can help
Bring a water sample to Top Dog Pool Supply. Local pool owners get a free water test on our Taylor Xpress Flex system, and we'll tell you what to add, and how much, for your pool's size.
Visit us at 7440 District Blvd Suite B, Bakersfield, CA 93313, or call (661) 664-9000. We're open Monday to Friday 9 to 5, Saturday 9 to 4, and Sundays 10 to 4 from April through September.