Hot Tub Water Maintenance: Best Expert Advice

Published on

April 16, 2023

Hot tub maintenance is perceived as a demanding task but it's necessary if you want to use your spa safely.There are over 5.8 million hot tubs in American homes, which is not surprising given that a high-quality hot tub can last 20 years or longer. 

But how can you make your hot tub last that long? How to avoid it and how to make the most out of your bathing experience?

In this article, we put up a beginner's guide to hot tub maintenance. Following these simple tips, you will find out how to keep your water clean and clear.

Maintenance Basics for Hot Tubs

You need to get acquainted with these terms if you want to become a hot tub maintenance pro:

  1. Circulation
  2. Filtration
  3. Hot tub chemicals

1. Circulation 

Circulation in your hot tub helps prevent contamination by bypassing the hot tub filter.

You can install an automatic flow control in your hot tub to make sure that water flows once or twice daily. This cycle circulates the fluid for around 10-15 minutes, ensuring that the filter absorbs all moisture.

Turn off your spa for 20 to 20 minutes twice a day for fresh water.

2. Filtration

A clean hot tub filter is priceless, as it guards against murky water, foul odors, bacteria, and the dreaded algae bloom.

Keeping the spa filter clean is also essential for hot tub maintenance if you want to avoid cloudy water. Hot tub filters need cleaning, depending on how frequently you use them.

A hot tub filter can become clogged and rendered ineffective with body lotion, hair gel, or other body-care products in the water. Regardless of how recently your spa filter has been serviced and cleaned, these products can still result in murky water. Keeping hot tub filters clean is essential.

Using a hot tub filter cleaner and degreaser regularly can extend your spa filter's life and save money. If you don't have a product like this on hand, you can clean the filter with dishwashing detergent (the kind you would use for hand-washing dishes, not automatic dishwasher detergent).

Keep your hot tub water clear and clean by cleaning your spa filters regularly. We recommend that filters be changed every 6–12 months and cleaned every 2–4 weeks (depending on usage). Using a garden hose, rinse the filters out of the tub and remove them from the tub. Soak them in a filter-cleaning solution overnight for a more thorough cleaning process. Use the product's label as a guide.

Pro tips:

  • Allow the cleaned hot tub filter cartridge to dry before reinstalling it in your filter completely.
  • When the spa filter becomes damaged or stops working, replace it. You'll notice this if the filter quickly becomes dirty after cleaning it.
  • Turn off the built-in water heater if you're cleaning your filter cartridge in a dishwasher. Water temperatures above 140 °F (60 °C) can damage the filter.
  • Run your hot tub's filter system for 3-6 hours each day. 
  • When cleaning or replacing hot tub filter cartridges, always wear gloves.

3. Hot Tub Chemicals

Regular hot tubs need regular chemical treatments to keep the water pathogen free.

Here is a list of the main hot tub products and their purpose.

Type of Hot Tub Chemical Purpose
PH balancer Brings pH levels to a level between 7.2 and 7.4.
Spa sanitizer Eliminates bacteria and other pathogens that cause diseases, such as E. Coli[1] and Legionella.[2][3][4]
Hot tub shock Provides a high amount of sanitizer. We recommend it in case of extreme contaminant build-up.
Calcium hardness increaser Increases the calcium hardness of the hot tub water.
Hot tub clarifier Eliminates cloudiness and leaves the water clear.
Line flush cleaner Cleans the hot tub’s plumbing.
Hot tub enzyme Controls the proliferation of organic contaminants[5] and bacteria.
Hot tub scale preventers and metal sequestrants Eliminate scale and metal residue, which prevents hot tub deterioration and high contaminant levels.

Some people use other products that are not commonly used for hot tub maintenance, this is why they are called unconventional:

  • Vinegar
  • Olive oil
  • Baking soda
  • Diluted bleach

Balancing Hot Tub Water Chemistry

The most important part of tub maintenance is chemistry balance. If you overlook this aspect, all others are useless. Here is what you should consider:

  1. PH
  2. Total alkalinity
  3. Hardness
  4. Calcium hardness
  5. Sanitizer
  6. Shocking
  7. Descaling
  8. Defoaming
  9. Water testing
  10. Other techniques

1. PH

PH is a measure of the acidity or basicity of your water. The pH scale runs from 0 to 14, with 7 being neutral. Anything below 7 is considered acidic, and anything above 7 is considered basic.

Maintaining the proper pH level in your hot tub is essential to preventing skin irritation, cloudy water, and calcium buildup.

The ideal pH level for hot tubs is between 7.4 and 7.6.

You can balance the pH in your hot tub as follows:

  • If the pH level of your water is too low, add a pH increaser such as sodium carbonate.
  • If the pH of your water is too high, add a pH decreaser such as muriatic acid or sodium bisulfate.

Muriatic acid can be used to modify the pH of your solution. It can cause severe damage to the hot tub surface if used in excess. The pH of your water can be maintained by adding spa enzymes, which break down organic materials in the water.

2. Total Alkalinity

Total alkalinity is a measure of the ability of your water to resist changes in pH, as follows:

  • Water with a high alkalinity level is less likely to experience drastic changes in pH.
  • Water with a low alkalinity level is more likely to experience drastic changes in pH.

The ideal alkalinity level for hot tubs is between 80 and 120 ppm.

Test the total alkalinity of the water and check the pH. Make any necessary adjustments. Retest both to ensure they're within acceptable limits.

You can balance total alkalinity as follows:

  • If the alkalinity level of your water is too low, add an alkalinity increaser, such as sodium bicarbonate or calcium carbonate.
  • If the alkalinity level of your water is too high, add an alkalinity decreaser, such as muriatic acid or sodium bisulfate.

High pH or alkalinity is most likely to blame for a cloudy tub. Adding a flocculent, which clumps the particles together, will allow them to be filtered out if the water is only somewhat hazy. Drain the tub and start over if the water is unclean.

3. Hardness 

Measure your water hardness using a test strip and follow these instructions in case you experience an imbalance:

  • If it's too low, add a hardness increaser.
  • If it's too high, drain 6 to 12 inches of water and add fresh water. Wait for 2 to 3 days, then test the water again to see how hard it is.

4. Calcium hardness 

The most straightforward technique to keep your hot tub's calcium hardness under control is to utilize soft water. Scales[6] build in your hot tub in case of too much calcium hardness. To protect yourself from these scales, apply a spa defense solution.

If your spa's calcium hardness is insufficient, the water will begin to draw minerals from other sources, such as the hot tub shell, resulting in discoloration and etching.

5. Sanitizer

The best way to treat hot tub water is to maintain consistent bromine or chlorine level in the water. This kills bacteria and other contaminants that can cause the water to become cloudy or smelly.

Here is a list of the most common types of sanitizer for hot tubs:

  • Chlorine or bromine granules
  • Chlorine or bromine tablets
  • Chlorine gas (mostly used by professionals)
  • Bromine liquid.

It's impossible to say how much sanitizer is needed because every hot tub owner uses their hot tub differently. If your water doesn't require any adjustments, we recommend testing and monitoring the amount of disinfectant and PH more frequently and making adjustments as needed.

6. Shocking

Shock treatments break down sanitizer residue and other contaminants, which would otherwise provide food for bacteria to thrive on. You can use chlorine shock treatments or non-chlorine shock treatments on your sanitizer.

Balance the spa water once a week, and remember to perform a shock treatment after a rainstorm, water change, or if the water appears cloudy.

7. Descaling

Your tub may need to be descaled frequently if your water is particularly hard. Mineral build-up can result in foamy water and make it difficult for chemicals to work properly. Use a commercial descaling product or a vinegar-water solution (1 part vinegar to 3 parts water) to remove mineral deposits. The vinegar-water solution or the product label instructions should be rigorously followed.


8. Defoaming

Foamy water is often caused by using too much soap when bathing or by using harsh soaps and shampoos that contain chemicals that can interact with the hot tub's chemicals, causing foam.

Body oils, cosmetics, lotions, and other goods are frequently implicated. You can avoid frothy water by following a water maintenance routine and showering before entering a hot tub. 

Keeping the defoamer on hand, on the other hand, is an excellent idea, especially if you're hosting a party or have new hot tub visitors.

To eliminate foamy water, first, check the pH and alkalinity levels. If they are not balanced, make the necessary adjustments. If the problem persists, try adding a defoamer to the tub. Follow the instructions on the product label. To altogether remove the foam, you may need to add the defoamer more than once.

Hot tub foam can be caused by a number of things, including:

  • Body oils and lotions
  • Detergents from swimsuits
  • Organics in the water
  • pH imbalance

To get rid of hot tub foam, you'll need to adjust the pH and alkalinity levels in the water. You may also need to add a clarifier to remove small particles that are causing the foam. Foam can also be caused by using too much hot tub product, so follow the manufacturer's directions.

9. Testing Hot Tub Water

Testing spa water is essential for maintaining safe water. A test strip lets you know quickly & precisely the levels of the:

  • Sanitizer
  • PH
  • Total alkalinity

The resulting chemical adjustments can be made as needed. All owners of hot tub facilities are responsible for monitoring and sanitizing their baths every day, as the water requires regular cleansing. If using an experiment strip, a person needs to follow the directions on the bottle for better reading carefully.

Test the contents of your water weekly using test strips[7]. Make any necessary adjustments to your fluid composition. It would help if you kept a routine for hot tubs to boost the spa maintenance program. Your hot tub skills will increase as you learn more sophisticated jobs, reducing unpleasant surprises. 

10. Other techniques

Besides what we have presented above, there are other techniques to keep balanced water chemistry for hot tubs:

Make hot tub water maintenance easy with the O-Care Water Expert App.

Hot Tub Cleaning – Step by Step

Follow these steps to provide proper cleaning for your hot tub:

  1. Clean the lines
  2. Drain the water
  3. Clean the hot tub surface
  4. Refill the hot tub with fresh water
  5. Add chemicals to balance the water chemistry

Step 1. Clean the Lines

Hot tub lines can accumulate build-up, resulting in hazy and odorous hot tub water. Reduced jet pressure can potentially be a result of the accumulation.

Before draining the hot tub, clean the pipes with a line flush or plumbing cleaning. Line flushing directions differ by product, so read them carefully.

While you're at it, give the hot tub cover a quick once-over with a 10% bleach-to-water solution to keep mildew at bay. A weekly clean is essential for hot tub care.

Step 2. Drain

Over time, minerals, chemicals, and other soluble compounds absorb your spa water, raising Total Dissolved Solids (TDS). The same principle applies to adding sugar to a cup of tea until it no longer dissolves. TDS reduces the efficiency of spa chemicals, resulting in flat, hot tub water that is more difficult to maintain.

With the preceding in mind, BISHTA recommends changing the water in a small (2-3 person) domestic hot tub every 3-4 months and more frequently (every 4-6 weeks) in more oversized hot tubs or those in constant use.

While you don't have to drain and refill your spa after every use, every three to four months helps remove built-up dirt, oils, soaps, and other potential contaminants that can cause cloudy water. It's good to drain and refill your tub when you can no longer see the bottom drain.

Step 3. Clean Hot Tub Surface and Cover

Hot tub surfaces are usually cleaned with substances and sponges that don't affect the material they are made of. We don't recommend using harsh chemicals for this step because the residue can affect the hot tub water balance. Natural products, such as sodium bicarbonate, will suffice if the spa is not scaled.

Periodically cleaning your spa cover reduces your workload. Follow these steps for a correct cleaning process:

  • When using it regularly, you should clean it every two weeks with a mild detergent and a soft brush.
  • If it's been a while since you've used it, give it a deeper cleaning.
  • Remove it, take it apart if possible, and wash all the surfaces with a mild detergent.
  • Before placing it back in the hot tub, rinse it thoroughly and let it dry fully.

Step 4. Fill With Freshwater

To avoid adding dirt and debris to your hot tub, use a grade hose with a backwash filter attached when changing the water. Drain the old water into a large container or outdoors.

Fill the tub halfway with clean water and test the pH, alkalinity, and calcium levels. As needed, adjust the levels. After the new water has been appropriately balanced, turn on the built-in heater and add your preferred chemicals to the tub.

Step 5. Add Chemicals

This table lists the ideal levels of chemicals for hot tub water.

Water Test Ideal Levels
pH 7.2 – 7.6
Total alkalinity 80 – 120 ppm
Calcium hardness 200 – 400 ppm
Chlorine 3 ppm[8]
Bromine 3 – 5 ppm

Here are some tips on how to add chemicals to the hot tub water:

  • Never mix spa chemicals, always add them separately.
  • You can either sprinkle the granules over the water or dilute them in warm water to add chlorine.
  • To avoid overdosing, we recommend adding chlorine in tiny doses at first.
  • After that, wait around two hours before retesting. This lets the chlorine do its job, so if the water is filthy, you may need to add more chlorine.
  • As a general rule, if you use sanitizer tablets, is that the first dose should be no more than one tablet every 100 gallons (450 liters).
  • Skimmer baskets or floater devices can be used to introduce tablets to the water, allowing them to disintegrate over time.
  • After adding chlorine to the spa, please wait at least 15 minutes before using it to allow the chlorine to do its job correctly.
  • If you have an extensive spa, or if the water is filthy, you may need to increase the number of chemicals you use.
  • Generally, hot tub chemicals are measured in parts per million (PPM). Maintain a concentration of between 3 and 5 parts per million (ppm). It's best to keep your bromine level at 2-5 ppm if you are a bromine user.
  • You can reduce the amount of time you spend on hot tub water care by using a quality filtration system and adding a clarifier to your routine. These two steps help you maintain clean water with fewer chemicals.

Pro Tips for Spa Care

Here is a list of pro tips for hot tub maintenance:

  • If you're going to be away from town for an extended period, don't switch off the power.
  • Cover your hot tub to make hot tub maintenance a breeze. When the hot tub isn't covered, the heater needs to work much harder to keep the water warm. It also causes higher water evaporation and necessitates the use of extra chemicals to balance hot tub water. Use a spa cover appropriately when the hot tub isn't in use.
  • Avoid covering the hot tub with plastic or other material that could trap heat and cause the spa to overheat.
  • Make sure you have a constant hot tub water level. If the hot tub's water level is too low, the pump can get damaged because of the air that can get stuck inside.
  • If you want to use fewer chemicals during your hot tub maintenance, using the O-care  Weekly Spa Care considerably reduces the amount of sanitizer you need to add to the spa water. It also provides a natural water feeling and leaves your skin soft, eliminating the need to shower after using your hot tub.

Simplify your Hot Tub Maintenance with O-Care.
Simplify your Hot Tub Maintenance with O-Care.

Hot Tub Maintenance Schedule

Simplicity and consistency are the key elements of the regular maintenance of hot tubs. Work is less stressful when it is broken up into small pieces that are easy to handle. 

This strategy, known as chunking, is employed by educational and commercial leaders worldwide to increase productivity.


  • Test the water if you use the spa frequently.
  • In case the water chemistry is off, balance it as described above.
  • Verify the temperature to avoid system damage.
  • Make sure the spa cover is not damaged and clean.


  • Check pH and alkalinity levels and balance them, if necessary.
  • Test the sanitizer levels.
  • Sanitize or shock the spa water in case of an unbalance.
  • Remove debris if needed.
  • Swipe the hot tub cover.
  • Make sure to rinse the spa filter using solely water.


  • Clean the filters thoroughly using chemicals.
  • Test that the jets are working properly.

Every 3 to 4 months:

  • Provide a chemical soak for your filters.
  • Wash the pipes of the hot tub system.
  • Change the water in the system (drain, clean, refill, balance).


  • We highly recommend a professional check-up once a year.
  • Flush the system to provide proper circulation.
  • Check the wires to make sure they are not damaged.


Hot tub maintenance is not complicated if you take into account three essential elements: circulation, filtering, and water chemistry balance. If you understand how to provide balance to your hot tub, you can provide safety for the users and prolong the lifespan of your hot tub. This can be achieved by keeping a strict schedule, especially if you use your spa often.