Does Shock Clear a cloudy Hot tub?


A cloudy hot tub isn’t as big of a problem as a cloudy pool. The pool water is on display, while the hot tub remains a more private affair. Still, disgust sensitivity keeps us from dipping in water that appears milky. And if you want to really clean your tub, you definitely need shock. But does that clear the water?

Shock can clear a cloudy tub only if minerals are the cause of its cloudiness. You can detect mineral-produced cloudiness by looking for crystalline residue. If the water feels slightly powdery, then you can be sure that an excess of minerals in the tub is responsible for its cloudiness.

However, excess minerals are far from the only cause of cloudy tub water. If your hot tub is cloudy for other reasons, then shock will not make it clear. In this article, you will learn how to pinpoint the causes of cloudiness and their adjacent solutions, including shocking the tub.

Why Is My Hot Tub Cloudy?

The solution to any problem, including a cloudy hot tub, starts with knowing the problem. As you can see, shocking the tub works, but only if the cloudiness has a very specific cause. So before you shock your tub, make sure you know why its water isn’t clear. Here are a few reasons to consider.

The Tub Water Is Old

Your hot tub’s filter mechanism is meant to keep it free of impurities to an extent. After a while, old water is old water, and cloudiness is among the symptoms that expose it. This cloudiness is caused by a buildup of body grease, which a hot tub’s filter isn’t good at getting rid of.

Knowing that water can get cloudy with time is important. It can help you assess how often you need to replace the tub water, so you don’t get worried about the cause of cloudiness each time the water stops losing its clarity.

The best way to test whether the lack of clarity is due to the water getting old is to simply look at the last time you filled the tub and how much you have used it since.

If your tub’s been used more than two times a week for over 4 months, then it is due for a water replacement. Draining previous water and filling up the tub with fresh water will clear up your hot tub.

The Filters Are Dirty

Another cause of cloudiness is running the water through a dirty filter. It is surprising how often this happens, but detergents, body oils, and other greasy products can get lodged in the filter. These products solidify when the heat pump is off. When the hot tub is used, a small volume of grease liquefies and gets injected back into the tub.

You need to clean the filter of your hot tub every two weeks. Black Diamond Stoneworks Spa Filter Cleaner helps you do this quickly because it comes in a handy spray bottle with just the right concentration to clean the filter in a single spray-and-rinse session. That is why it has a global average rating of 4.5/5 stars from over 1600 reviews and ratings. Its ease of use is rated at 4.6!

There Is Body Care Product Residue in the Hot Tub

Even if your filter pump doesn’t have solidified detergent stuck in it, body care products can wreak havoc on the clarity of your hot tub water. Shocking the tub will not affect water made cloudy by soap and other body care products.

There are only two possible solutions to this. The first is to drain the tub and refill it, and the second is to measure and neutralize the pH imbalance in the hot tub. If you’ve been using the tub water for three months, you need to get rid of it. It’s too old anyway, and there is no point in wasting pool chemicals on it.

The pH of the Hot Tub Is Too High

If the pH of the hot tub is high, the water is more basic than it is acidic. Water in the tub can become very obviously cloudy when it has too much basic content. A high pH is an indicator of high alkalinity, which can result in white chemical deposits in the plumbing of your hot tub. 

When these deposits are fragmented by running water, they produce a cloud that is responsible for the “cloudy” appearance. Generally, this problem (alongside high alkalinity) is the most common cause of a milky hot tub. And you can simply lower the pH of water by shocking the tub.

The Alkalinity of the Hot Tub Is Too High

Since pH indicates acidity and alkalinity, you cannot lower pH without introducing acidity or reducing alkalinity. As mentioned earlier, water that has an alkaline nature leads to mineral deposits. These deposits can be detected by looking for powdery residue in a sample of water.

If your tub’s cloudy water has a powder-like source, then you need to add chlorine, which can reverse the cloudiness. Please note that shocking the hot tub doesn’t always clear its plumbing. If your tub pipes have scales, you need to drain the tub and use anti-scaling liquid to clear them.

Exact Steps To Take When Your Hot Tub Is Cloudy

Since hot tub cloudiness is most often caused by high alkalinity and pH, you might want to start your deduction there. But the solution for an alkaline tub is far more effort-intensive than that of other minor causes. These steps will help you clear a cloudy hot tub with the least effort required:

  • Take a glass full of water from your hot tub and analyze the cloudiness. 
  • If the cloudiness is oily/milky, you must refill your hot tub with fresh water.
  • If the cloudiness is powdery, you need to shock the tub with the respective shocking agent you generally use.

Final Thoughts

Shock clears a cloudy hot tub in well over 50% of the cases because it lowers the alkalinity of the water, and it is high pH that results in cloudiness. But if your water is old, oily, or full of body detergent, then its lack of clarity is harder to offset. For that, you need to refill your hot tub with fresh water.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

Recent Posts