You’ve had a long day at work and are looking forward to enjoying a nice soak in your hot tub when you look at the water and notice it’s cloudy. How did this happen? How can you fix it? How do you ensure this never happens again?

Below you’ll find the most common reasons for cloudy, hot tub water, how to treat it and how to make sure it doesn’t affect your spa again.

The Causes for Cloudy Hot Tub Water

Poor Filters

A poorly-fitted or dirty filter isn’t completing its job, meaning particles it would normally catch are left in the water to decompose.

Nature’s Droppings and Algae

Dead leaves, seed pods, grass clippings and a host of other things shed by nature can land in your hot tub when you’re using it or if it is left uncovered. These contaminants can quickly clog your spa’s circulation system and filter, meaning they rot and cloud up your spa.

Another one of nature’s “gifts” for hot tubs is algae. Usually caused by poor water chemistry, the algae will continue to multiply and die in your spa—leading to gross water.

Not Enough Sanitizer

When you don’t use enough sanitizer, all of the things our bodies slough off (from body oils to fecal matter) lingers in the water, causing a cloudy appearance.

Bad Chemistry

Optimizing spa water is a science, and if the water isn’t in balance, you can easily find your water looking cloudy.


Bacteria is smarter than we give it credit for, covering itself with a thick, disinfectant-resistant film and nestling in your hot tub’s plumbing.


If your water has a high mineral and metal content, it’ll lead to poor water quality, unsightly stains and cloudy water.

Clearing the Water

Clean and Run the Filter

Look if your filter is gunked-up and thoroughly clean or replace it. Also remember that your filtration system needs to run a minimum of one hour, twice a day.

Shock the Water

When in doubt, shock algae and contaminants out. Depending on how much use your hot tub gets, plan on shocking it at least once a week.

Become a Chemist

If you haven’t already, test your water’s chemical levels to make sure they’re correct and adjust accordingly.

Metal Sequestrant

If you know heavy metals are clouding up your water, a weekly metal sequestrant treatment combined with filling your spa with filtered water will clear issues right up.

Flush Your System

Whenever you change the water, flush your spa lines by using a flush product. Remember to flush before you drain.

Drain and Refill

You should already drain every 3-4 months, but after exhausting all options, you should flush your system, add a new filter, drain and clean the shell and fill it with filtered water.

Preventing Cloudy Hot Tub Water

  • Buy a hose filter and only use filtered water in your spa.
  • Follow a maintenance schedule that includes regular water balance checks.
  • Regularly check and clean or replace your filter.
  • Change your water every 3-4 months and use a flush product every time.
  • Make sure your hot tub has enough sanitizer.

Spa Maintenance with Mountain Leisure Hot Tubs

Remember that cloudy water is usually easily treated and prevented if you use the right tools.

We are pleased to off service packages for those who would like to trust us with their spa’s maintenance. If you’re interested in purchasing a hot tub, look at our selection here.