You may be wondering the things that are responsible for the foam in your hot tub. A soak in clean and clear water is one of the best experiences you can have as a hot tub owner. But as a spa owner, you are bound to face some hot tub problems and challenges as you use your spa. Some of which are due to lack of maintenance, while the rest are due to natural causes.
Foamy hot tub water is one of the problems you will face, and the following factors are the common causes of foam in a hot tub:
- Low calcium hardness
- Body lotions and oils
- Soap and detergent
- Poor water balance
- Biofilm build-up
- High or low pH level
- Leaves and debris
- Chemicals
- Low or high alkaline level
Read further to learn how to handle each of these problems.

The importance of maintaining your hot tub
Your hot tub needs to be maintained as regularly as possible so that you can enjoy all the benefits that come with owning a hot tub. The following are the reasons why you should maintain your hot tub;
- It is very beneficial to human health example:
- A good hot tub helps one to have a better sleep.
- A good hot tub helps in weight loss.
- A good hot tub helps to reduce stress.
- A good hot tub helps in muscle relief.
- A good hot tub helps to prevent cardiac problems and so many more.
- To keep it free from contaminants: maintenance of a good hot tub helps to make sure that the hot tub is free from contaminants like germs, bacteria, and other pathogens. A well-maintained hot tub also helps to prevent scum.
- To ensure good circulation of water: if your hot tub is not maintained correctly, it may cause damages to the pump, jet, and other parts which control the circulation of water in your hot tub. Therefore, maintain your hot tub for a good circulation of water.
- To ensure prolonged efficiency: a good maintained hot tub tends to last and operate better and longer because a hot tub has adequately maintained the filter, the jets, the heater, the Ozonator, the pump, the pillow, and other parts of the hot tub will last longer.
- To prevent leakage: when your hot tub is not maintained correctly, it can lead to a lot of damages to several parts of the hot tub. When components like the pump, filter, or pipeline are damaged, they can leak in your hot tub.
- To prevent cloudy hot tub water: you need to maintain your hot tub to avoid the hot tub water from being cloudy, dangerous to your hot tub and you.
- To prevent a foamy hot tub, you prevent your hot tub water from becoming foamy when you maintain your hot tub properly.
- To reduce the cost of repairs: when you maintain your hot tub regularly, it saves from the cost of constant avoidable repairs.
Why does your hot tub foam?
As a hot tub owner, you will experience a foamy hot tub once or twice, as the case may be. There are various reasons why you see foam in your hot tub. It can be because of maintenance issues or natural phenomena. The following are the reasons why your hot tub water gets foamy.
- Low calcium hardness
Low calcium level damages the part of your hot tub. It also reduces your water‘s surface tension, which leads to excess foaming. Typically calcium levels are acceptable and rarely need adjusting, but when you live in areas with hard water, that’s when it becomes a problem.
You can prevent low calcium hardness by testing your water weekly with a hardness tester. If the water is low on calcium, use a calcium increaser to your water, but drain it all and refill with tested and treated water if it is high.
- Body lotions and oils
Oil and lotion build-up are some of the commonly known causes of foamy hot tub water. As you soak in your hot tub, you unintentionally realize oil, deodorant, body lotions, shampoo, hair care products, and other beauty products into your hot tub water. When these products are present in your hot tub water, but in small quantities, the adverse effects are not severe but, if not taking care of, can build up on the surface of your hot tub water and form foam.
You can temporarily treat this by shocking the water and permanently by adding some filtration chemicals like sanitizer.
- Soap and detergent
The easiest way for surfactants to enter your hot tub is through soap residue from your skin which enters the hot tub when you soak. When soap enters your hot tub water, it reduces your water’s surface tension, thereby making it easy to foam. Also, detergent had the same effect on your hot tub as soap; it reduces your water’s surface tension. Foaming caused by detergent is mainly from improperly rinsed bathing suits. Your hot tub bathing suit is one of the easiest ways for the detergent to enter your water while you are soaking. you can clear foamy water caused by soap and detergent by shocking the water
you can prevent it by rinsing yourself and your bath suit properly before using it to enter your hot tub.
- Poor water balance
Poorly balanced hot tub water can be indicated by foamy hot tub water. This poorly balanced water can end up damaging part of your hot tub over time. An inadequate water balance reduces the surface tension of your hot tub water, and when it does this, it gives room for germs and other hot tub issues to arise. But when you determine the cause of your water-poor water balance, you can make the necessary adjustments and clear the foamy in your hot tub. You can also prevent this by constantly checking your water balance and making the necessary changes.
- Biofilm build-up
Biofilm is any group of pathogens or microorganism that sticks them to a surface which is in regular contact with water. Your hot tub temperature can be said to be mild enough to allow these pathogens and microorganisms to create a habit in your water. If these organisms are not treated early and adequately, they may end up sticking to a part of your hot tub like plumbing. When these pathogens and micro organism stick to your plumbing, it will be difficult for sanitizers like bromine and chlorine to treat them effectively. The more these pathogens begin to grow in your hot tub water, the more they reduce your water’s surface tension and then start to form foam.
- High or low pH level
When your hot tub pH level is low, it affects your water chemical balance, making it prone to germs and pathogen infestation. Also, a high pH level can lead to an imbalance in your hot tub water, leading to dirty and foamy hot tub water. By daily testing your pH level, you can determine your hot tub water’s chemical and water balance. If your pH level is low, you need to increase it to at least 7.5 with a pH raised, whereas if your pH level is high, you need to reduce it with the aid of a pH decreaser.
- Leaves and debris
Sometimes, a foamy hot tub is caused do due to the actions of nature. When leaves fall from trees and air particles bring debris into your hot tub, they decompose and form foamy water. You may be depending on your hot tub sanitizer to kill the debris and leaves. Do not forget that sanitizers only kill algae and bacteria. Therefore if you do not remove the leaves by handpicking method, the bacteria and algae can begin to attach to the leaves, and the sanitizer will not be able to do its job correctly. And this can lead to cloudy and foamy hot tub water.
- Chemicals
When you do not add a sufficient amount of chemicals into your hot tub water, it will not have a maximum effect on the germs and debris present in your hot tub. If you use the wrong chemical on your hot tub, it can also cause your hot tub water to foam. Chemicals like low-grade chlorine or bromine products, low-grade algaecides, biguanide sanitizer chemicals, or household cleaners can cause your hot tub water to foam.
- Low or high alkaline level
When your hot tub alkaline level is low, it affects your hot tub chemistry, likewise when it is high is alters the total water chemistry, and it causes water imbalance. Therefore if your alkaline level is low use an alkaline increaser to boost it whereas if your alkalinity level is high use a PH decreaser to balance it.

How to clear a foamy hot tub
A foamy hot tub is not a very serious danger to your hot tub until you allow the germs and contaminants to accumulate in your hot tub. The saturation level of your hot tub water is depending on the number of germs present in your hot tub water. When your hot tub becomes highly saturated no amount of filtration or addition of chemicals will clear the foam in your hot tub water. And you have to drain the hot tub entirely and refill the hot tub.
Some helpful products you can use to clear your hot tub based on the cause of the foaming
Some products can be of help to you in clearing your foamy hot tub. the following are some products that you can use to clear your foamy hot tub when it is still at the early stage.
Hot tub defoamer – a hot tub defoamer is an anti-foaming chemical additive that is in chemicals that reduces and hinders the formation of foam. Hot tub defoamers are available at many local hot tub dealers. You can also use vinegar to make your homemade defoamer.
How to make use of vinegar as a hot tub defoamer
Add vinegar to your hot tub water in the ratio of 1:10 but ensure that your hot tub water has been recently shocked to enhance the efficiency of the defoamer.
Another method is by adding vinegar and baking soda to the water. This should be done in the ratio of two parts of vinegar, one part baking soda, and nine parts water. Baking soda and vinegar will react and kill the contaminants responsible for your foamy hot tub water.
Vinegar is a simple and effective household cleaner therefore it will serve as a very effective defoamer.
Oxidizing shock – an oxidizer is a chemical that causes impurities to break down quickly. Oxidizing Shock is the shocking of your hot tub higher than the normal number of times. They can be in powdered, liquid form, or composition. Before shocking your hot tub you need to check the type of sanitation system your hot tub is running on. Shocking your hot tub will temporally clear the causes of your foamy hot tub. but it is advisable to shock your hot tub water every week.
Use a pH adjuster – sometimes, your foamy hot tub can be a result of your chemical imbalance. Therefore if the pH of your water is responsible for the chemical imbalance you need to adjust it with the use of a pH increaser or a pH decreaser as the case may be.
Hot tub scum buster – a scum buster is a substance that is used to remove scum formed in your hot tub water. A scum buster eliminates grease, grimy hot tub rings, and scum.
Enzymes – enzymes are organic catalysts that can destroy or decompose organic molecules. The smaller molecules are now destroyed by disinfectants. Organic wastes like sweat, lotion, mucus, dead skin, etc are contaminants that cause your hot tub to become foamy. Some of these contaminants are readily removed by chlorine while the rest will react slowly with chlorine. The enzymes help to preserve the bromine and chlorine sanitizers thereby boosting their efficiency.
Enzymes help improve the hot tub water quality, it reduces the amount of chlorine and bromine required to maintain your hot tub. It also helps to clear, reduced, and prevent. They also improve your hot tub experience.
Oil absorber – oil absorbers are pads, boom, or sponges that are used to absorb lotion, oil, and any other liquid substance that contaminate your water.

Steps on how to remove foam from your hot tub water
To bring back the smooth and relaxing experience your hot tub gives you every time you soak, you need to clean and maintain it regularly. Whenever you experience foamy hot tub water here are some guidelines on how to clear it.
- Test your water
The first line of action to take when you notice any foamy buildup in your hot tub is to test the hot tub. By testing you need to check the water balance and the water chemistry; that is the pH level of your hot tub, the alkalinity level of the hot tub, calcium hardness level, and the sanitizer level. The reason for testing your water is that an imbalance in water and chemical levels can make your hot tub water foam.
You can make use of a test strip, a test kit or you can take a sample of your water to a hot tub dealer to test your water for you to be sure of the cause of your foamy water.
- Rebalance your water
When you rebalance your water you need to ensure that you rebalance both your water and the chemical level. By water rebalancing your water chemical level you need to
- Add a pH increaser if your hot tub water’s pH is below 7.4-7.6
- Add an alkalinity increaser if your alkalinity level is lower than normal
- Add pH decreaser to your hot tub if your pH and alkalinity level is high
- Add calcium increaser if the calcium level of your water is low
- Add Sanitizer to your hot tub water depending on the type of hot tub sanitation system your hot tub runs on.
- Remove impurities
If after rebalancing your hot tub water and you still notice foam at the surface of your hot tub water, you need to remove the buildup of lotion, oil, hair products, and soap. While you are doing this you cannot use the hot tub because the absorber needs days to soak in all the contaminants on your hot tub water. You should also remove any visible contaminants like leaves, insects, and other organic matter to help the absorber work efficiently. If after a week and the foam does not clear or subside, you will need to add another absorbing sponge to help quicking the process so you can enjoy your relaxing hot tub again.
- Drain Your hot tub water
If after removing the impurities in your hot tub and the foam remains, it will be best for you to drain your hot tub water. For chemicals, shock, or absorbers not to work in your hot tub it means that your hot tub water has become highly saturated.
Steps on how to drain your hot tub water
- Use a line flush product, and use it according to the instructions written on the product package.
- Turn off your hot tub switch and disconnect every electrical
- Trip the breaker of your hot tub
- Remove the filter
- If the filter is still good you can just clean it thoroughly but if it is not manageable replace it with a new one to be safe.
- Drain the hot tub with a drain plug or sump pump.
- Clean your hot tub and Refill
Since you are draining your hot tub it will be a good idea to use the opportunity to also clean your hot tub as well. You can use the appropriate cleaner to clean your hot tub, especially at the curved edges. After cleaning your hot tub properly you can then refill your hot tub.
Steps on how to clean and refill your hot tub
- After draining your hot tub, clean the interior surface with vinegar and water in a ratio of 1:4
- Rinse the inside of your hot tub thoroughly
- Wipe the inside thoroughly
- Ensure you remove all the traces of cleaner to prevent the water from becoming foamy again.
- Replace your filter with the cleaned or new one.
- Refill your hot tub, I recommend you attach a hose filter to your garden hose to prevent chemical impurities.

For quick fixes
In case you have an emergency activity or Party and you do not have the time to follow the following above procedures there are some chemicals you can use to clear your foamy hot tub water temporarily.
- Use a foam defoamer
A foam deformer is an anti-foaming chemical that can clear all the foam in your hot tub and it can last for 24 hours. But do not forget to follow the above procedures after your party because a foam defoamer can only remove the effect of the foam but it can’t remove the cause.
- Use a hot tub clarifier
You can also deal with foamy hot tubs by using clarifiers. If you can’t trace the cause of your problem, you can use a clarifier because its function is to track down and bind itself to the organic matter. Therefore, you can add a small amount of clarifier with the jet and run for about an hour. If done properly, the clarifier should gather and bind with what is making your hot tub water foamy.
- Use of hot tub shock
A hot tub shock can help clear the foam in your water but only temporarily. When you want to shock your water as an alternative to Following the steps on how to clear your hot tub which may last for days, ensure you check your hot tub owner’s manual to know the type of sanitation system your hot tub runs.
How to maintain your hot tub
For a hot tub to give you a satisfying feeling, you need to maintain it properly and regularly. You can do that by obeying the following:
- Daily maintenance – for an optimal experience in your hot tub, you need to perform the following daily maintenance:
- Check the pH level of the water to make sure it is not above or below the expected level. If it is, use a pH increaser or pH decrease to return it to 7.6.
- Checking the sanitizer level of the water to make sure it is not low; if it is, you need to add more sanitizer.
- Putting additives in the water to prevent the problem of germs.
- Check for any broken or damaged part of the hot tub to make sure it can perform effectively.
- Check the alkaline level of the water to make sure that it is not below the expected level.
- Run the hot tub at high speed to enhance filtration.
- Weekly maintenance – the following are activities that have to be followed weekly to make sure your hot tub is safe and always ready for use:
- Shock your hot tub water to help kill bacteria.
- Add an instructed amount of sanitizer into the water to help kill the germs.
- Add a small number of enzymes into the water to kill germs.
- Add a small quantity of vinegar to the water to help kill germs and other organic matter.
- Use of manual or robotic vacuum cleaner to clean the pool to keep it free from algae.
- Monthly/sporadic maintenance – the following are activities you have to do monthly, after a couple of months, and some once a year.
- Clean the filter at least after every two months either by soaking, spraying, or rinsing to improve its efficiency.
- Add salt to your hot tub water monthly, depending on times of usage, to help kill germs.
- Change the old water by draining and refilling it with well sanitized and treated water.
- Change and replace worn-out and damaged parts to improve efficiency.
- Others: these are things you are expected to do; they do not have time limits.
- Avoid eating and drinking in the hot tub.
- Make sure you cover the hot tub to prevent air particles and dead organic matter from entering inside.
- Make sure you keep to a simple cleaning routine.
- Always close the air valves when the hot tub is not in use.
- Always sanitize was you are done with the hot tub.

The problems that may arise when your hot tub becomes foamy
A foamy hot tub can lead to a lot of problems to humans as well as the hot tub if not dealt with properly, and they are as follows:
- It causes infection – foamy hot tubs cause infections like respiratory difficulty and hot tub rash to anyone who uses it due to the various germs, pathogens, and other harmful microscopic substances present in the water.
- It reduces the efficiency of the hot tub – if the hot tub water is foamy, it can affect some parts of the hot tub like the jets, pump, etc, the contaminates can clog and block the filter and pump.
- It causes corrosion – soft water is one of the causes of foamy hot tub water and can cause corrosion of the hot tub components.
- Uncomfortable soak: a hot tub is meant to make you feel relaxed and stress-free, but when it is foamy, it becomes uncomfortable, and it loses its natural water feel and its excellent hot tub experience it gives.
How to prevent foamy hot tub water
You do not need to wait for your hot tub to become foamy before taking care of it. Foamy hot tub water can be prevented by following some maintenance procedures:
- Constant cleaning of the filter – To ensure that your hot tub is always cloud-free, ensure you constantly clean your filter at least once a month, and also do not forget to change it when it becomes unmanageable. Also, use solvents to remove the oil and grease in the filter at least every two-month interval.
- Always close the air valve when the tub is not in use – Make sure that you always close the air valve when the hot tub is not in use to enhance the circulation of sanitizer and to enhance the filtration process.
- Change your water occasionally – The water can get worse due to air particles and other kinds of stuff, so try as much as possible to occasionally change your water at least once every four months to prevent building a home for microorganisms.
- Avoid frequent use of lotion – Lotions and hair products tend to use up the sanitizers in the hot tub; therefore, avoiding the use of lotions can help boost the water chemical balance and keep the water cloud-free.
- Run the hot water pump for at least two hourly daily by doing this it helps to enhance the filtration process and keeps the hot top crystal clean.
- High-speed pumping: You need to pump your hot water at high speed for about two hours to make sure that it is filtered effectively.
- Check and fix/repair worn out parts: Hot tub needs to be checked often to make sure that all the part all the loose part is fixed and all the damaged part are replaced for safety reasons.
- Shock water regularly – Try to shock your hot tub water at least weekly to make sure it is germs-free.
- Place your hot tub filter properly – Sometimes, the wrong positioning of the hot tub filter cartridge leads to cloudy hot tub water; therefore, ensure that the cartridge is fully seated on both ends to prevent water from bypassing the filter cartridge. Also, try to spray or soak the cartridge with a spa filter cleaner to remove the greasy or mineral deposits before cleaning for a free flow of water in your filter.
- Regular sanitizing – Sanitizing is very important because when you are done soaking, some germs are washed off from your body. But those germs will remain in the hot tub, which, if not treated properly, can develop into an oil buildup. Therefore, the best way to kill the bacteria and keep the water clean is by regularly sanitizing, if possible, after every use of the bathtub, especially soakers, by adding a recommended dosage of bromine or chlorine and allow it to settle, but if you are sensitive to bromine or chlorine, you can make use of other sanitizers like a mineral cartridge or an Ozonator.
- Drain and refill – As long as you want a foamy-free hot tub, and you need to drain the old water and refill it with a sanitized and balanced one at least every four months.
- Use vinegar – Try using white vinegar once in a while to treat your hot tub water to prevent germs and air particles from contaminating the water.
- Add clarifiers to the water at least weekly to help kill germs, organic particles, and other contaminants.
- Ensure you cover the hot tub when it is not in use to help to prevent air particles from contaminating the hot tub water.
- Avoid eating and drinking in drinking while in the hot tub to prevent spilling drinks or dropping food into the hot tub.
- Regular inspection – By regular inspection of the pipes and equipment before the hot tub pump can help to fix the source of the air leak with sealant or lubricants.