Pool Cloudy After Adding Chemicals

What Causes the Cloud?

Chlorine is what clears a pool, so when a cloud appears it is almost always a response to something else sitting in the water. The usual causes are calcium dropping out of solution as tiny white specks, a pH that has drifted up too far, or stabilizer that has piled up over the seasons.

Your test kit gives you the pH, a number that shows how acidic the water is. Pools do best between 7.2 and 7.8. Climb above that band and the water may turn hazy, the chlorine loses some of its power, and scale can start building on surfaces and gear.

Calcium hardness simply means how much calcium is dissolved in the pool, and the target range is 200 to 400 ppm (parts per million, the unit test kits use). Water heavy in calcium turns cloudy unless alkalinity or pH sits low enough to hold it in balance.

Before you add anything else, test the water so you know what you're fixing. Get alkalinity right first, then pH, because alkalinity is what holds pH steady. While you're at it, check calcium and stabilizer too.

Cloudiness After Baking Soda Goes In

Baking soda pushes total alkalinity up, and alkalinity is what keeps the pH from wandering. If the water already holds a lot of calcium, extra alkalinity upsets the balance that was keeping that calcium dissolved. Soon after the baking soda goes in, a milky haze shows up.

A calcium hardness test will show whether your pool fits that picture.

Adding Calcium Too Close to Baking Soda or Soda Ash

Put calcium chloride in within a few hours of baking soda or soda ash and the water will turn cloudy. To avoid this, space the calcium treatment and the alkalinity products apart on different days or at least well away from each other.

Also, do not pre-dissolve calcium chloride in a bucket. Instead, scatter it across the water surface with the pump running so it spreads evenly.

Does Chlorine Itself Cloud a Pool?

Not on its own, since chlorine is what clears a pool. But adding it can nudge the pH up for a while, and that short-lived rise is enough to leave some calcium behind as a fine white haze.

The product you poured matters too. Some household bleach has extra ingredients mixed in, so it helps to read the label and check if what you added was plain pool chlorine or a bleach with extras in it.

Metals in the water can also react to chlorine, though they tend to give a green or brown tint rather than a milky one. A white or gray cloud usually traces back to calcium or pH.

Bringing Down Excess Calcium or Cyanuric Acid

Cyanuric acid, the sun-shield for chlorine that most people call stabilizer, can add to the haze when it builds up too high. The target level is 30 to 50 ppm. If your reading sits above that, moving to unstabilized chlorine stops it from climbing further.

To lower high stabilizer, drain part of the pool and refill it; to lower high calcium hardness, the replacement water needs to have lower calcium hardness.