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There are hundreds of catchy named hot tub chemical products that are marketed to solve specific problems that you may face during hot tub ownership. Do you need to use products that are specifically labeled for hot tubs or will chemicals you have around the house serve the same purpose?
There are numerous household items that you can use to maintain your hot tub. Items such as vinegar, baking soda, and chlorine bleach can all be used to replace specifically labeled products to maintain your hot tub.
What other household items can you use? You may be surprised to learn that there are many common household items that can be used in your hot tub. The real question is, will this save you any money? I will break it down for you.
What Are Common Hot Tub Chemicals?
When you have reached a state of hot tub nirvana, you shouldn’t need to mess with your hot tub’s water chemistry very much. Adjusting the pH and sanitizer levels when needed and a good filter cleaning and shocking routine should keep your hot tub fresh and ready to go.
While that is all you “should” need, there are going to be times when something is just off. And that is ok! We have all been there.
So what are some common hot tub chemicals?
The two most common sanitizers are chlorine and bromine. I use chlorine because have had bad skin reactions to bromine in the past, but both are very common in hot tubs. Spoiler alert! I have not found a household replacement for bromine.
There are multiple types of hot tub shock which if you are interested in learning more, please check out my article about shocking your hot tub.
The two most common ways to shock your hot tub is with a chlorine-based product most commonly dichlor shock or a non-chlorine-based product most commonly an oxygen/potassium derivative abbreviated as MPS.
Alkalinity and pH Adjustment
I have combined pH and Alkalinity together because in general their movement is intertwined. Lowering the pH in your hot tub will also lower the Alkalinity and raising the Alkalinity will also raise the pH.
One of the most frustrating things for me when adjusting my hot tub chemicals after a fresh fill is getting the pH balanced. My tap water has very high alkalinity, close to 300. Since alkalinity acts as a buffer to pH, I have to drop the alkalinity significantly before I will see the pH move to where it needs to be.
The chemical used to lower alkalinity (and pH) is sodium bisulfate.
To increase alkalinity (with a small impact on pH) you can use sodium bicarbonate. To increase pH (and alkalinity) you can use sodium carbonate.
A metal sequester is a product commonly used in hot tub water care. Its main purpose is to keep dissolved metals in the water from staining or damaging the hot tub surfaces. Most products achieve this using soluble metal chelators. A chelator is a binding agent that suppresses chemical activity.1
In the case of a metal chelator, the product binds to metal ions in the water a prevents them from being oxidized. The oxidation of a metal such as iron creates red rust stains that may permanently damage the acrylic shell of your hot tub. So it is important to stop this process before it happens.
Almost every hot tub owner will have to deal with foam from time to time. The most common cause of foam in my experience is soaps, lotions, and products brought into the hot tub by its users. Ensuring your guests shower or rinse off before entering the hot tub should help reduce this cause of foaming, but it may still happen from time to time even with the strictest of policies.
This is a perfect scenario for a foam reducer product which is generally some form of silicone or non-silicone product that quickly breaks down the existing foam and prevents additional foam from forming temporarily. A really simple example of this in action is when you add cooking oil to a boiling pot of water that is bubbling over.
Other causes of foam are improper water balance, dirty filters, or water that needs to be changed. You can check out my guide to changing a filter where I will teach you how to get the most out of your filter so you can save money.
If improper water chemistry is causing your foaming issue, you will need to properly balance the water before you will be able to fix your foaming problem. In my experience, the foaming problem will usually disappear after the water is balanced and your sanitizer levels are adequate. If this doesn’t fix your problem then you might need to drain your hot tub and start over. With a fresh fill, I can teach you how to make your water last longer.
Cloudy water can sometimes be remedied by a water clarifier. One method of achieving this is using a product that binds to contaminates and helps them stick together. The goal is to create clumps that are large enough to be picked up by your hot tub filter. Another type of water clarifier is an enzyme-based product that breaks down the contaminants.
Both types can work well depending on your situation and preference.
What Household Items Can Replace Hot Tub Chemicals?
Cost: $4-$5 per gallon (9-12 cents per 3 oz use)
Yearly Savings: Significant!
Uses: Sanitizer, Chlorine Shock
Bleach is Sodium Hypochlorite or in other words chlorine in its pure form. In general, bleach bought in the store is diluted down to 6-8% sodium hypochlorite. In general, this means you will need about 3 oz of bleach (assuming 6% dilution) to bring a 500-gallon hot tub from 0 ppm to 3 ppm of free chlorine.
- Inexpensive compared to granular chlorine
- Don’t have to worry about CYA
2. Baking Soda
Cost: $0.50-$1.00 per lbs
Yearly Savings: Significant!
Uses: Alkalinity Increaser, Foam Reducer (with Vinegar)
Baking Soda is sodium bicarbonate which is the same chemical in spa-branded Alkalinity Increasers. The conversion is generally 1:1 between baking soda and spa-branded products assuming they are 100% sodium bicarbonate.
- Inexpensive compared to Alkalinity-Up
- Easy to find in stores
3. Washing Soda
Cost: $1-2 per lbs
Yearly Savings: Significant!
Uses: Alkalinity Increaser, pH Increaser
Washing Soda is sodium carbonate which is the same chemical in spa-branded pH Increasers. The conversion is generally 1:1 between washing soda and spa-branded products assuming they are 100% sodium carbonate.
- Inexpensive compared to pH Increaser
Cost: $2-$3 per gallon
Yearly Savings: Depends on the use
Uses: Foam Reducer (with Baking Soda), Cleaning agent
Vinegar is a great natural cleaner. Using it to clean your hot tub is a perfect way to avoid harsh chemicals and potentially save some money in the process. For spot cleaning a 1:1 ratio of vinegar to water works wonders.
- Easy on hot tub surfaces and your skin
- Natural foam reducer
How To Make A DIY Foam Reducer
Foam in a hot tub can be an annoyance. Even if the water is perfectly maintained it can give the perception that the hot tub is dirty. There are a lot of products on the market that will help temporarily reduce foam and if you aren’t the DIY type then I would get something like this foam reducer.
If you want to try a DIY solution, follow the very simple guide below. I hope you find it helpful!
What you need:
- Resealable Bottle
- Baking Soda
- Tap Water
- Fill a gallon jug with 90 oz of water (11.25 cups)
- Add 10 oz of baking soda
- Mix until all the baking soda has disolved
- Add 20 oz (2.5 cups) of white distiled vinegar to the water and baking soda mix
- Mix until fully combined.
If you want to scale the recipe yourself here is the ratio: 2 parts vinegar to 1 part baking soda to 9 parts water.
Add a capful or 1 tablespoon to your hot tub water at a time with the jets running until the desired effect has been achieved (a.k.a the foam is gone).
Can A Hot Tub Be Truely Chemical Free?
No, a hot tub cannot be completely chemical-free. In general, to be safe for use, a hot tub must maintain a low level of sanitizer between 0.5 to 3.0 ppm if using chlorine. However, with supplemental products and discipline, the chemical level can be kept as close to the low end as possible.
I was a competitive swimmer in a past life, so I spent more hours a day in a pool than I did sleeping. Waking up at 4 am 6 days a week so I could take the cold plunge into our training pool for morning practice was something I used to live for. Not really, I hated the early morning practices, but I loved the sport so I put up with the schedule.
Because I was in the water so much I quickly realized that I was extremely sensitive to chlorine and bromine. The pool we trained in was used constantly so naturally it was heavily dosed with chemicals to keep it clean. What did this mean for me? My skin was miserable during the competitive season which ran from October through February. I had severe eczema breakouts, which at times were all over my body and I eventually started using an inhaler because I was so sensitive to the gasses coming off of the pool.
The whole point of this story is to say that I completely understand the want and desire to find a chemical-free solution to water maintenance. Here are a few ways you can get as close as possible to a chemical-free system, coming from a guy who understands what it is like to need a better solution.
Disclaimer: Please make sure that you always follow local laws, regulations, and health requirements when maintaining your hot tub.
A mineral system uses what the name suggests, minerals dissolved in the water, to help support your sanitizer so it can be more efficient at sanitizing which means you will need less of it. These systems are great because they allow you to bring your sanitizer level down to 1.0 ppm which is close to drinking water levels. There are a bunch of products on the market but only a few that I will recommend.
Product Link: Frog @ease
I use this system now and it is by far the easiest system I have used to date. The system contains a mineral cartridge and a sanitizer cartridge. The mineral cartridge only needs to be replaced once every four months or after every fresh fill. The sanitizer cartridge will last up to 4 weeks depending on the size of your hot tub and the frequency of use.
After every fresh fill, you balance your water chemistry like normal then pop in the Frog @ease cartridge and you are good to go. Once a week you can check your water chemistry and adjust pH and Alkalinity as needed (I have found I rarely need to adjust using this system). At the same time, you can check to make sure the sanitizer cartridge isn’t empty. If it is, simply pop in a new one.
This system keeps a constant chlorine level right around 1.0 ppm which has been great on my skin. The only downside is the cost. But for me, the low time investment, convenience, and low chemical levels are worth it.
Product Link: AquaFinesse
I have not used this system, but I know there are many people in the industry that absolutely love it. As a mineral system, it uses minerals to change the water properties and make your sanitizer work better. AquaFinesse has the added benefit of making the water feel very soft on your skin. Of the people that use it, this is the #1 remark.
This system is more expensive than the Frog @ease system and does not include a sanitizer cartridge. Meaning, you will have to add your own sanitizer to the hot tub water. With that being said, this system is still a great low chemical alternative with the added benefit of providing a skin-soothing experience.
Product Link: Nature2 Mineral Stick
I have used the Jacuzzi branded version of this product in my hot tub. Nature2 is a mineral stick product that uses minerals and silver ions to help sanitize your hot tub water. It is also marketed to help keep your water chemistry balanced. I had trouble with this system, but it was also the first system that I ever used so some of my issues could have been due to my inexperience.
The mineral stick fits inside your filter, or in your filter compartment depending on the brand of hot tub you own. It is good for the life of the water in your hot tub or 4 months. It does not replace a good sanitizer routine so, like the Aquafinesse product, you will still need to add your own sanitizer. It is a relatively inexpensive option that provides some additional benefits and gets you closer to a low chemical system.
An enzyme system is an intriguing product. It provides your hot tub water a boost by using enzymes to break down organic material so that your sanitizer can eliminate them. These systems are able to break down oils, lotions, soaps, and other organics introduced into the water. Because of this unique ability, they should help make your hot tub water last longer. This saves you time and money. Besides, who wants to drain and fill their hot tub in the dead of winter because their water chemistry has gone haywire.
There is only one product on the market that I have heard good things about, so if you are interested in trying this system, the choice is easy.
Product Link: Spa Marvel
I have not used this system, but it is a fascinating science to me so I will definitely be trying it out for myself. As mentioned above, Spa Marvel is an enzyme system, so it breaks down organics in the water through the use of enzymes. Their system includes a water treatment/conditioner, cleanser, and filter cleaner.
The water conditioner (enzyme solution) does the brunt of the heavy lifting and needs to be added once every 3 months. The beauty of this system is if your water chemistry and clarity good, then all you need to do is add another bottle of the enzyme solution and you are good for another 3 months. I have heard of users going an entire year on the same water using this system.
The Spa Marvel system will allow you to maintain a very low sanitizer level of 0.5 to 1.0 ppm making it a low chemical alternative.
Salt Water Systems
A saltwater system uses salt to generate chlorine through a process called electrolysis. The benefit of this system is it maintains a constant level of chlorine in the water which helps avoid the typical yo-yo’ing that a traditional manual sanitization process would cause. The stable sanitizer level will, in theory, allow a lower overall level of sanitizer because there is less of an opportunity for nasties to form.
Hot Spring is the largest hot tub manufacturer that sells an onboard saltwater system. Many users rave about this type of system. A salt system still requires proper water chemistry maintenance so it is not completely worry-free, but it can reduce the amount of time you spend maintaining your hot tub.
There are retrofit products available that can convert an existing hot tub into a saltwater system, but a built-in system is probably better. One downside is the replacement salt cartridges can be expensive and under heavy bather loads, supplemental sanitizer may still be needed.
If you are opposed to adding supplemental products to your hot tub or are on a very limited budget, you can still achieve a lower chemical soaking experience using a more traditional water maintenance routine. It will take a bit more trial and error to dial in the right process for your particular situation but with some patience, you will get it down.
The trick? Add sanitizer after your soak in just enough quantity that the next time you want to use the hot tub, the levels have dropped to 1.0 ppm. The general rule of thumb for granular chlorine is 1 tsp per person, but this can vary based on your situation which is why it will take you some time to zone in your exact recipe for success.
This method is by no means foolproof. I used this method in the past and found that if I didn’t use the hot tub often enough, the sanitizer levels would drop too low before my next use which meant I needed to add more between uses. If you use your hot tub daily this shouldn’t be a problem, but if you don’t, you will need to remember to add more sanitizer every few days to maintain a high enough level that the water stays clean.
I eventually grew tired of this constant attention and opted to spend a little extra money to save myself some hassle. That was my choice, and something you will have to decide for yourself. If done properly, this method can work for you.