Why Is My Pool Cloudy After Shocking?
A pool that turns cloudy right after shocking is usually reacting to the shock itself. Granular shock (calcium hypochlorite) adds calcium and raises pH, and in Bakersfield's hard water that can push calcium out of the water as a white haze. Dead algae and a dirty filter can do it too. Run the pump nonstop, bring pH back to 7.4 to 7.6, and clean the filter. Most pools clear in a day or two.
What makes a pool cloudy after shock?
- Calcium from granular shock. Calcium hypochlorite adds calcium every time you use it. In hard water, the extra calcium can turn the water milky.
- High pH. Shock raises pH for a while, and above about 7.8 calcium comes out of the water as a fine white haze.
- Dead algae. Shock kills algae, and the dead algae floats as a gray or white haze until the filter catches it.
- A dirty or worn filter. If the filter is already loaded, it cannot catch what the shock just killed.
- Shock added the wrong way. Granules dumped in one spot, or added with the pump off, cloud the water more.
How do I clear a pool that is cloudy after shocking?
- Step 1: Run the pump 24 hours a day until the water clears.
- Step 2: Test pH and bring it to 7.4 to 7.6. Lower high pH with muriatic acid, following the label.
- Step 3: Brush the walls and floor so settled haze gets back to the filter.
- Step 4: Clean the filter. Hose off the cartridges, or backwash a sand or DE filter. You may need to clean it again the next day.
- Step 5: Still hazy after 24 to 48 hours with good test numbers? Add a clarifier, which clumps fine particles so the filter can catch them.
- Step 6: Retest chlorine before anyone swims.
How do I keep it from happening again?
In hard-water areas like Bakersfield, shock with liquid chlorine instead of granular calcium hypochlorite. Liquid chlorine adds no calcium and no stabilizer. Add shock in the evening with the pump running, pour it slowly around the edge of the pool, and check pH before you shock. We carry HASA liquid chlorine in disposable containers and in a returnable 4-pack crate.
When should I bring in a water sample?
Bring a sample if the water is still cloudy after 3 to 4 days of nonstop filtering, if it turned green or brown instead of white, or if it clouds up every time you shock. We'll check calcium, alkalinity, stabilizer, and metals, and tell you what is causing it.
How long does a pool stay cloudy after shock?
Usually a few hours to a day. If it lasts longer than 48 hours with the pump running nonstop, check pH and calcium and clean the filter.
Is it safe to swim in a pool that is cloudy after shocking?
Not yet. Wait until you can clearly see the main drain at the deep end and chlorine is back under 5 ppm.
Does liquid chlorine make a pool cloudy?
Rarely. Liquid chlorine adds no calcium, so it is the better choice for shocking in hard water. If the water clouds after liquid chlorine, the usual cause is dead algae or a dirty filter.
Should I add clarifier right after shocking?
Wait. Give the filter 24 to 48 hours first and get pH in range. Clarifier works best once chlorine has dropped back toward normal.
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.