Why Is My Pool Water Brown or Rusty?
Brown or rusty pool water usually comes from one of three things: iron or other metals in the water, fine dirt and dust, or algae. Metals turn the water tea-colored but leave it clear, and it often happens right after you add chlorine. Dirt and algae make the water cloudy. The fix is different for each, so test before you treat. Top Dog Pool Supply checks for iron and copper free with every water test.
What turns pool water brown?
- Iron. It comes from well water, old pipes, or rusting metal parts. Chlorine turns dissolved iron into rust, so the water goes brown soon after shocking.
- Dirt and dust. After a wind storm or a muddy rain, the water looks brown and cloudy, and dirt settles on the floor.
- Algae. Mustard algae looks like yellow-brown dust on shady walls. A badly neglected pool can turn brown-green.
- Leaves. Leaves soaking on the bottom release tannins that tint the water and stain plaster brown.
How do I tell which one it is?
- Look at the water. Clear but tinted points to metals. Cloudy points to dirt or algae.
- Think about timing. Brown right after shocking or refilling points to iron. Brown after wind or rain points to dirt.
- Brush a wall. If a brown or yellow dust lifts off easily and comes back in a day or two, it is likely mustard algae.
- Bring in a sample. Our Taylor Xpress Flex test checks iron and copper along with the usual levels.
How do I fix brown pool water?
- Step 1: Stop shocking until you know the cause. More chlorine makes a metal problem look worse.
- Step 2: For metals, add a metal control product such as Orenda SC-1000, following the label. It binds the metal and helps keep it from staining.
- Step 3: Keep pH at 7.4 to 7.6. High pH helps metals drop out and stain.
- Step 4: For dirt, brush, vacuum, run the pump nonstop, and clean the filter. A clarifier helps with fine dust.
- Step 5: For algae, brush, shock, and hold chlorine high until the water clears.
- Step 6: Clean the filter once the water clears, because it will be holding what it caught.
When should I call for help?
Bring in a sample or call us if the water is still brown after a few days, if brown or rust-colored stains are showing up on the plaster, or if the color came back right after a refill. If your fill water carries iron, we'll help you set up a routine that keeps it from staining. Rust-colored water can also come from a failing heater or other metal equipment, and we repair those.
Why did my pool turn brown after I shocked it?
Chlorine reacted with iron in the water and turned it to rust. The water is usually clear but tea-colored. Stop adding shock, use a metal control product, and bring in a sample.
Is it safe to swim in brown pool water?
Wait until you know the cause. If you cannot see the bottom, do not swim. Metals can stain hair, nails, and swimsuits, and cloudy water hides swimmers in trouble.
Will brown water stain my pool?
It can. Iron leaves brown or rust-colored stains on plaster if it sits. Treat it quickly and keep pH in range.
Can well water turn a pool brown?
Yes. Well water often carries iron. Test the fill water, and add a metal control product whenever you top off or refill.
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.