Hot Tub Shock Treatment (The Complete Guide)

Hot tub shock treatment is one of the vital aspect of spa maintenance. This might sound shocking, but sanitizers aren’t a great option if you are thinking long-term. It quickly wears off and can be overrun by more bacteria than the average in your hot tub. A preferable option is to use a shock treatment. Since water stays in your hot tub for extended weeks to months, you would want to ensure it remains clean- more reason why you should have a grasp on hot tub shock treatment.

What is hot tub shock?

Hot tub shock is the addition of an oxidizer to “shock” the water, making it clean and free from contamination. You could use chlorine or non-chlorine shock. This treatment is to remove cloudy water and bad smell by breaking down the organic waste contaminants. The water clarity and quality will also be fully restored after treatment.

hot tub shock treatment

Occasional hot tub shock is necessary for a clean, transparent hot tub system regardless of the sanitizer you use. Besides, it can impact your sanitizer system to function more efficiently. The following are reasons why you should engage in a periodic hot tub shock:

1. It wipes out Organic Contaminants: You move in with all sorts of organic contaminants whenever you enter your hot tub. Remnants anything your body comes in contact with like lotion, shampoo, lotion, dead skin cells, makeup, sunscreen, hair, etc. Plus, if you share the bathtub with another person, imagine the contaminants’ volume from all the people bathing in the water. It’s terrifying.

By showering before any dip in the bathtub, you can lower the organic contaminant content. But it wouldn’t work so well. They might still be some irritating stuff that requires sanitizers. But again, it can’t go so far, as the sanitizers wear off quickly. A hot tub shock remains the best option to tackle contaminants’ accumulation that may cause problems like cloudy water and hot tub scum.

2. It Kills Bacteria: A bacteria triggers color stains on your stuff like curtains and walls. When it leaves a pinkish stain, it’s bacteria and not rust as many people think. You can quickly eliminate this by washing your curtains, but it’s not the same with illness-causing bacteria. Here, it’s better to apply preventive measures. Hot tubs are famous for being a brooding space for these three kinds of illness-causing bacteria:

  • Legionella leads to a chronic type of pneumonia, Legionnaires’ disease.
  • Pseudomonas Dermatitis results in hot tub folliculitis
  • Non-tuberculosis mycobacteria result in hot tub lung, a granulomatous lung illness.

You can keep these bacteria and others away by ensuring sanitizer levels and water balance stay steady. However, in between the chemical application and water tests, sanitizers can be employed to maintain water cleanliness. Hot tub shock will enhance and eliminate whatsoever might be breeding in the water before making anyone ill.

3. It Removes Chloramines or Bromamines

What you perceive in a public pool is not the chlorine but chloramines in the real sense. Chlorine leaves off some waste products when being used in removing and killing bacteria and organic contaminants. The chloramines are what you perceive. You will also inhale them until the sanitizer level is balanced.

Hot tub shock creates the balance easily and eliminates chloramines from the water, thus eliminating the smell and enabling you to breathe well. Bromine also releases waste products called chloramines if it’s your sanitizer. Although the smell isn’t close to chloramines, it’s something you wouldn’t appreciate breathing in. Shocking your hot tub will make the bromine content balanced. It’s also a means of maintaining it.

Types of Shock for Hot Tub Treatment

There are various types of available hot tub shock. However, only apply specified hot tub chemicals. It’s a small water body and heats up faster than pools, which implies that you might get a reaction different from an application in the pool. Avoid destroying your manufacturer warranty by using only labeled spa chemicals. Below are the types of hot tub shock:

  • Non-Chlorine Shock: It’s necessary to note that non-chlorine shock isn’t a disinfectant. Meaning it doesn’t eliminate bacteria. So what’s the relevance anyway? Its most popular effective agent, potassium peroxymonosulfate, is an active oxidizer. When applied weekly, it effectively removes organic contaminants such as lotions and skin cells and clarifies if the contaminants make it a bit cloudy. If you follow this method, try regularly to monitor the chlorine level and ensure it doesn’t dip below 1ppm. However, if your sanitizer is chlorine, it kills bacteria by activating free chlorine. The same goes for bromine.
  • Calcium Hypochlorite: Although widely available and inexpensive, Calcium Hypochlorite is better used for pools and not for hot tub shocking. This is because Calcium Hypochlorite, also known as Cal hypo, is unstabilized chlorine, meaning its effectiveness will wear off by 95% after its exposure in your hot tub for few hours. Its content includes calcium which means it will quickly leave off components and scales on surfaces in your spa, which can cause some issues.
  • Lithium Hypochlorite: You can check for this shock type in your remote pool or hot tub supply store. However, Lithium hypochlorite isn’t as accessible as before because lithium is now majorly used to produce lithium batteries. This also impacts the price of manufacturing materials, thus making it more costly than before.
  • Biguanide: In the real sense, this option is hydrogen peroxide, but not one to store in your medicine box, therefore don’t assume you can use it and be perfectly good. Manufacturers who produce the biguanide sanitizer generally have a stretch of products (water clarifier, oxidizer, test strips) produced to function with biguanide.
  • Minerals: You need to add a small amount of chlorine when using the spa mineral sanitizer for effective results. However, ensure the chlorine level is at 0.5 pm if you have also applied the chlorine shock to avoid having too much chlorine in the water. This doesn’t imply that you should apply a chlorine shock. If you have issues with algae, bacteria, or low chlorine, chlorine shock is a great option.
  • Dichlor: Dichlor shock is the active content in many hot tub shock brands. You don’t necessarily need to dissolve it before adding it to the water, but it’s recommended that you follow the package’s specified guidance. It features a small cyanuric acid content, which implies that it’s more stabilized and can measure up to the spa heat. However, still, monitor the sanitizer level, and shock it day and night if it’s under any structure or outside to prevent the sun’s rays from quickly absorbing the chlorine.
  • Salt Water: Chlorine can be changed to salt with the salt chlorine generator, which sanitizes your spa, making chlorine shock the best option. If you are worried about high chlorine levels in the bathtub, you can also use non-chlorine shock.


If you frequently use your hot tub or have several people sharing it with you, it is advisable to stick with a chlorine shock to keep the water in good condition and free from contaminants. Similar to chlorine usage, you can also employ non-chlorine shock frequently for the same purposes. However, chlorine shock remains the best option.

How long should you wait after shocking hot tub?

Chlorine or any other hot tub sanitizer option is essential in making the water in your tub clean, clear, and fresh. However, since chlorine is a potent chemical, it may result in various problems if misapplied. If you need answers to how long you need to wait after adding the chemical, here is the answer:

You need to test the water after adding chlorine to it and hold until the chlorine levels have dipped to a recommended certain level of around 2 and 4 parts per million. This might require few hours or oven 24 hours for the levels to dip based on the amount of chlorine you added to the water. Getting in before time may expose you to respiratory problems or the chlorine irritating your skin. Regardless of whether the levels appear safe, it’s still advisable to hold for a minimum of 30 minutes to prevent highly concentrated sections and enable the chlorine to disperse into the water.

Safe chlorine levels in a hot tub

Unusually, you can’t directly head into a hot tub after applying chlorine or any other type of sanitizer. You need to let the chemical dissipate entirely into the water to prevent the chemical concentration in any area.

This doesn’t require much time, but it’s recommended you hold for a minimum of 30 minutes put on the jets to enable the chemical to absorb and circulate in the water. To allow the vapors to leave faster, it’s best to remove the hot tub cover during this period.

If you are applying chlorine as a sanitizer to your hot tub, you need to pour in enough water till it reaches around 5 and 8 parts per million. The water will receive an excellent chlorine boost, and the chemical will function effectively to remove any contaminant and make the water clean.

However, it’s not secure to bathe in levels between 5 and 8 parts per million as it can lead to skin and eye irritations and respiratory problems. This implies you need to exercise patience. Chlorine dissipated with time. Therefore the chlorine levels in the water will dip the longer you wait. You can frequently check the chlorine levels during the wait until it is around 2 and 4 parts per million certified.

How to check chlorine levels in a hot tub

Checking your chlorine level is easy. You need a test strip to dip in the water and then compare the resulting color with the key on the test strip port side. I’ve used these test strips for this job, and they work fine and are reasonably priced. This will tell you how much chlorine there is in the water.

Make sure that you keep the test strips in the waterproof container when you are not using them and when you get them out, be careful not to get any drops of water on them from your hand or to allow sweat or any other dirt or fluids from your fingers to interfere with the test strip.

How to reduce the level of chlorine in your hot tub

If the chlorine level in your hot tub is on the high side, asides from waiting, you can try out a couple of things. First, you can try reducing the water content in your hot tub by removing it and then refilling. Although this might be difficult, it is preferable that staying for the whole day to allow the chlorine levels to lower by themselves. You can also employ the sump pump to make the whole thing faster.

Have it in mind that the water you remove from the hot tub will also have high chlorine, which can be harmful to lawns and plants. Therefore you need to dispose of it wisely. Use clean water from a hose filter when filling up to ensure the water doesn’t have a high quantity of dirt or metals in it. After pouring the freshwater into the hot tub, you will see chlorine levels have reduced. You can now run the hot tub jets for some time to ensure the water dilutes together wholly.

If you are in haste and have a high chlorine concentration in your hot tub, you can employ a chlorine neutralizer like Sodium Thiosulphate. Attend to the guide on the package’s side and ensure to test the water again to know if it has safe levels of chlorine before entering into the tub. The neutralizer will work effectively, but it’s best to wait for the chlorine levels to dissipate naturally.

Is it secure to get in a hot tub with high chlorine levels?

It’s not a good idea to bathe in a hot tub with highly concentrated chlorine. As said earlier, chlorine is a strong chemical that can cause respiratory issues, air, skin irritations, and excessively itchy eyes.

This doesn’t mean you would have these issues if you bathe in excessive chlorine levels, but the risk is more. Bathing in hot tubs with high concentrations of chlorine is reportedly associated with various health conditions. It is better to follow the manufacturer’s guide and not put your health on the line.

Do note that settling in a hot tub means sitting in a chemical area. Therefore, the lower the chlorine content in the water, the better. Always endeavor to avoid excessive chlorine levels.

Are there any alternatives to using chlorine in a hot tub?

There are several hot tub options to using chlorine as your sanitizer. In recent years, many people are fast becoming enlightened of the health issues and environmental hazards traced to strong chemicals. You can sanitize your hot tub with UV or a natural saltwater solution. There are also ozonates and some other sanitization options where you don’t need to use harsh and strong chemicals.

how long to wait after shocking a hot tub

How long do you have to wait after shocking a hot tub to get in?

You can use your hot tub almost immediately if you are applying a non-chlorine or natural shock. However, you still need to wait for about 30 minutes for the chemical to dilute with the water. This guide is also applicable to you if you are using a chlorine or chemical shock. You need to monitor the chlorine levels and be sure it’s somewhere around 2 to 4 parts per million, considered safe and allow the chemical to disperse to this level before bathing in the hot tub. This process might take up to 24 hours.

You can save yourself the stress of having to allow your chemical levels to reduce and calculating if it’s safe for use by instead adding a shock or chlorine dosing before entering. This will go down well with most people who use their hot tub regularly or probably once a day.

Don’t forget to shock the tub after every usage, and then you will have the whole day for the chlorine content to deduce to safe levels. For safety precautions, it never a waste to run a quick water test before sliding into your hot tub to ensure everything is balanced. Following this water maintenance habit will keep your hot tub clear and fresh.

The best way to shock your hot tub

If you have ever attempted to study how to shock a hot tub, you will know it’s a pretty simple process. However, you need to follow show specified steps and safety precautions to get the best result from the hot tub shock.

Note the following relevant guidance when using hot tub chemicals:

  • Before using any hot tub chemical, always check the label and carefully attend to the instructions.
  • Unless recommended by a hot tub specialist, never dilute hot tub chemicals.
  • Never add water to the chemicals, but you can add chemicals to the water.
  • During use, never pour chemicals into your hot tub.
  • Use hot tub chemicals only in air-free areas.
  • When using powdered chemicals, be wary of strong winds.
  • All hot tub chemicals should be kept away from children and pets all the time.
  • After applying hot tub chemicals, ensure you wash your hands well.
  • It is advisable to always put on protective clothing when using the chemicals.
  • It is advisable to regularly test the water in your hot tub daily using any sanitization method like chlorine test strips, bromine, or any other you prefer.
  • Keep hot tub chemicals far from moisture and heat.
  • Please don’t turn off your hot tub, except you are changing the water in it or changing filters.

In this regard whichever, you will be needing:

  • Hot tub shock (chemical, non-chlorine, chlorine, etc.)
  • Test strips
  • Gloves (chemical-resistant)
  • Measuring cup (chemical-resistant)
  • Safety goggles

Once you have it all ready, you can proceed to work.

In seconds, run a test for the seven vital chemistries: Total Chlorine, Total Hardness, Free Chlorine, Total Bromine, Total Alkalinity, pH, and Cyanuric Acid.

  • Uncover Your Hot Tub: It is crucial its left uncovered during this process. After adding the water’s shock, some of it needs to disperse from the hot tub water. This is also applicable to any accessories like the floating thermal blanket that may spread over the water. Also, no one should stay inside the hot tub while adding the chemicals or spa shock.
  • Test the Water: The pH level must be at the recommended 7.4 and 7.6 levels before applying the hot tub shock. Immoderate levels in the hot tub (High or low pH) will impact the shock’s effectiveness and impede from functioning as it ought to. If it’s not at the appropriate level, correct it and proceed with shocking.
  • Turn Off the Blower: You need to leave the circulation pump to disperse the shock evenly in the hot tub. However, switch off the jets when the water moves but not too troubled to stop the shock from wearing off fast.
  • Wear your Safety Gear: You should pay adequate attention to your skin since shock and any other sanitizer you apply in your hot tub is a chemical. To prevent it from seeping into your eyes, you should put on your safety goggles. Also, consider dressing in a long-sleeved top, closed-toe shoes, and long pants in addition to wearing safety google and gloves.

If you keep your hot tub indoor, switch on an exhaust fan, open a window, or both. Regardless of how you go about it, ensure the room is well ventilated before opening and applying any chemical. If your hot tub stays outside, avoid shocking it when it’s not windy. Stay upwind from the hot tub when it’s windy, and position your hands closer to the water surface so that the chemicals won’t float around instead of entering into the hot tub. In case any shock spills, clear it on the instant and safely discard it. Ensure to keep hot tub shock away from children and pets every time.

  • Measure the Shock: Don’t try to four the shock from its package directly into the hot tub. Gauging with your eyes isn’t an option either. Measure the quantity of should proportional to the quantity of water in your hot tub. You can locate this info by checking the shock label. And if you are in doubt about the amount of water your hot tub holds, you can contact your manufacturer. Applying the method recommended by your shock producer, pour the shock into your hot tub carefully.
  • Leave the Hot Tub Uncovered: For a minimum of 20 minutes, leave the hot top open and allow the shock to dilute in the water. If you don’t intend to bathe in the hot tub immediately after you have finished shocking, cover the hot tub for about 20 minutes to avoid evaporation.
hot tub shock treatment

Caring For Your Hot Tub

Apart from shocking your hot tub occasionally, we recommend that you learn some good hot tub maintenance habits such as changing the hot tub water and cleaning the filters. This can help stall the build-up of contaminants in the water.

1. Changing your hot tub water

Water needs frequent replacement as you can only maintain it chemically for a short while before it becomes a platform for accumulating bacteria. You should change and refill the hot tub with water every three to four months. You can use a pipe cleaner or hot tub flush to draw out the water. This would help remove the calcium from the pipe hold and eliminate any debris you can wash off with the seeped water. It is also important to wipe clean your tub shell before refilling with water.

2. Filter Care

The water surface flows into the filter box and drains out the debris and dirt through the cartridges. The filter should care for based on your usage. However, we advise cleaning it every two weeks. Sharing with more people may result in a fast clog. It will be a different issue whenever you refill or drain, or spa or newly fill it. In this scenario, the filter may become blocked from the particles in the manufacturing or tap water particles.

It is recommended that you clean the filter frequently. Else the flow of water may be blocked, and the tub will shout immediately. You might get diagnostic alerts on your pad like Heater Dry, FLO, DR, LF, OHH if your filters are dirty.

To be sure the filter caused the issue, loosen it and, for a few minutes, run the hot tub to check if the display message clears. If it remains there while the filters are removed, turn on the hot tub and put it on back. Don’t try running the tub for too long without filters.

how to clean hot tub filter

How to clean the filters

The easiest way to clean them is by using a cleaner. To go about this, spray the filter with a filter cleaner evenly, then wash away after 15 minutes using a hose. As a second option, you can try soaking your filter overnight with a filter cleaner. This would give the filter an in-depth clean by breaking pleats and oils in it. Either of these options is excellent for maximum result.

FAQ on Hot tub Shocking treatment

Now that you understand how hot tub shock treatment works, you might still have some questions. Beneath are some answers.

How long do I wait after shocking the hot tub?

Once you are done shocking, there is no rule about when to get in. It is dependent on whether the shock content has reduced to the level it ought to be. You can only know if the level has dropped by testing the water. For unique guidance, you can also go through the manufacturer’s guidance.

How frequently should the hot tub be shocked?

You should shock your hot tub weekly or share it with many people you can do twice weekly. Always remember to test the water and ensure the pH level is where it’s supposed to be before shocking your hot tub. Also, ensure the cross-check if the sanitizer level is normal.

When Should I Shock My Hot Tub?

You can shock it whenever you choose if it’s inside. But if outside and not beneath a patio cover, you may need to hold till night or dusk. When using chemicals like dichlor, which has some stabilizer content, it is advisable to shade it from the sun’s rays to prevent burning out the chlorine before it takes its full effect.

Why is the cover of my hot tub waterlogged?

Hot tub covers are wrapped in polythene, produced from dense polystyrene, and dressed in vinyl. While new, it is strong and should be kept away from children and the garden’s intense heat. But when the cover is used over time, the ozone and corrosive chlorine used to remove the bacteria in the hot tub will destroy the polythene coating around the polystyrene body. After the use of over 4-5 years, the polythene becomes penetrable and enables the hot tub steam to come up till it’s too heavy to lift. You will need to purchase or get a new cover if this occurs.

You also need to treat your hot tub with a cleaner once every year to eliminate the biofilms and limescale that are hard to scrub from the pipe insides. Pour in the hot tub the system cleaner before the regular refill between 3-4 months and leave for an hour to circulate. Drain out once done and fill up with fresh water again, and you are okay. Remember to remove the filter and leave it in cartridge cleaner to soak and wash before fixing it back.


Shocking your hot tub is recommended for the safety of your bathers and keeping clean water. The chemicals eliminate contaminants and enhance your sanitizers in doing a good job. It can also save you the stress of having to drain out and refill your hot tub with water. Ensure always to use the shock carefully while paying attention to the package. Soak yourself in your hot tub, and enjoy the bathe!

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