Many people have a hot tub in their backyard. The pH of the water is important to maintain the longevity of the hot tub. Individuals who use their hot tub on a regular basis should take it easy adding chemicals to avoid any adverse effects on the hot tub, which can be expensive to replace if damaged by a chemical imbalance. The ideal pH range for a hot tub is between 7.4 and 7.6, and anything above this can cause issues with your hot tub. But how do you lower the pH in a hot tub?
How do I bring the pH down in my hot tub?
You can lower the pH in your hot tub by adding a pool acid-like Muriatic Acid or Sodium Bisulfate. This will reduce the total alkalinity and pH. The hot tub pH increases when the water becomes excessively alkaline, this causes the water to deteriorate. At this point, the overall alkalinity of the water in your hot tub will also be high.
There are different ways to lower the pH in a hot tub. In this article, I will provide more details on how you can bring down the pH in your hot tub. I will also answer some commonly asked questions.
- 1 How to Bring the pH Down in a Hot Tub
- 2 Frequently Asked Questions
- 2.1 – Why won't the pH level go down in my hot tub?
- 2.2 – Why is the pH in my hot tub always high?
- 2.3 – What do you do if your spa pH is too high?
- 2.4 – Can I use vinegar to lower the pH in my hot tub?
- 2.5 – Can you use baking soda to lower pH in a hot tub?
- 2.6 – How do I lower the pH in my hot tub without chemicals?
- 2.7 – What should be adjusted first, alkalinity or pH?
- 2.8 – Does chlorine raise or lower pH in a hot tub?
- 2.9 – Does pool shock or spa shock raise or lower pH?
How to Bring the pH Down in a Hot Tub
It is worth mentioning that there's no almighty formula for lowering the pH level in a hot tub. This is because hot tubs are different from each other, and they require different levels of maintenance and chemicals. Also, different factors can affect the frequency of chemically balancing your hot tub, the number of chemicals to add, and the level of maintenance.
The main factors that affect the chemicals and amount of maintenance include:
- The quality and source of water
- Cleanliness of bathers
- Hot tub's surrounding environment
- The size of the hot tub
- Use frequency
- Number of bathers
- Drain and refill intervals
- Water temperature
- Hot tub maintenance interval and quality
You'll need acid to lower both the pH and alkalinity of your hot tub. The most commonly used acids are sodium bisulfate and liquid muriatic acid. The pH lowering mechanisms are the following:
- Hydrogen ions: When mixed with water, the acid lowers the pH by increasing the concentration of hydrogen ions
- Bicarbonates: Also, the acids reduce the total alkalinity by reacting with bicarbonates in the water.
Using Muriatic Acid to lower the Hot Tub pH
As mentioned earlier, muriatic acid is a common chemical that is used for lowering the pH of water in a hot tub. The main reason why this acid is commonly used is that it is relatively cheap. However, there are a few risks associated with using this acid.
Muriatic acid is extremely corrosive, and it is available in both liquid and dry forms. To use this chemical, you'll need to ensure your safety because it can damage eyes, burn skin or cause lung and nose irritation. However, it lowers pH at a fast rate, and you can use it to kill algae and mold, dissolve buildup in your hot tub, and remove stains.
Here's how you can use muriatic acid to bring down the pH in your hot tub:
- First test the pH: Test your hot tub to know the pH level of the water in it. You can use a liquid test kit, a digital tester, or paper test strips.
- Check the needed quantity: Use the instruction on the bottle of the acid to know the quantity of acid to add to the water in your hot tub..
- Protect your eyes: Ensure you have your protective gear on. This includes safety goggles, resistant gloves, and a chemical mask. Wear long pants and sleeves so that the acid won't burn you if there's an accidental splash.
- Mix the acid with water: Make a dilution of 1 part of muriatic acid and ten parts of water in a large bucket. Use a wooden stick to stir the solution.
- Add to the hot tub: Pour the solution into the hot tub and leave for a few hours to circulate.
- Check the pH: Check the pH of water in the hot tub and adjust if necessary.
Using Sodium Bisulfate to lower the Hot Tub pH
Sodium bisulfate is a lot safer than muriatic acid, but a more expensive option. The acid is mostly available in the granular form because the dry acid is mild. Sodium bisulfate is also a great pH lowering agent that you can use in your hot tub. However, you'll need to exercise some level of caution when using this acid.
Here's how you can use sodium bisulfate to bring down the pH in your hot tub:
- First test: Test your hot tub to know the pH level of the water in it. You can use a liquid test kit, a digital tester, or paper test strips.
- Check the needed quantity: Use the instruction on the bottle of the acid to know the quantity of acid to add to the water in your hot tub.
- Protect your eyes: Protect your eyes with safety goggles, and your hands with chemically resistant gloves.
- Fill a bucket with water: Pour water in a large bucket before adding a measured quantity of the sodium bisulfate granules. Use a wooden stick to stir the mixture until the granules completely dissolve in water. This ensures that the granules do not damage your hot tub's shell.
- Make the solution: Pour the solution in your hot tub, and leave it to circulate for at least 3 hours.
- Check the pH: Check the pH of water in the hot tub and adjust if necessary.
Frequently Asked Questions
– Why won't the pH level go down in my hot tub?
If you notice that the pH level in your hot tub is excessively high and won't go down, it means that the alkalinity of your hot tub is too high. Use muriatic acid to lower it. Muriatic acid is a better agent than dry acid for lowering the alkalinity of a hot tub.
– Why is the pH in my hot tub always high?
The main reason why the pH in your hot tub is always high is that the total alkalinity is too high. Total alkalinity is the buffer that helps to keep the pH within range. However, if the total alkalinity itself is not in the correct range, it wouldn't effectively buffer the pH, and your hot tub pH will not be within the desired range.
Hot tubs have a relatively high water temperature. Combined with bubbles, this results in the production of carbon dioxide gas. A buildup of this gas can also cause the pH to increase.
– What do you do if your spa pH is too high?
If your spa pH is too high, you can try using any of the acids or methods we have mentioned above to lower the pH. Ensuring that the pH level of your spa is within the appropriate range will help you create a suitable environment for your baths. It will also keep your spa free of corrosion and minimize calcium buildup.
The products mentioned are not the only ones that can help. There are many options that can help to lower the pH of your spa. Check online or with your local dealer for more information.
– Can I use vinegar to lower the pH in my hot tub?
You can use vinegar to lower the pH of your hot tub. I recommend using up to four cups of vinegar and pouring it directly into the water in your hot tub. For this, you can either use apple cider vinegar or regular white household vinegar.
Let the water circulate for some time and measure the pH again. If it is still too low, you can add some additional vinegar. You can repeat the process until you reach the required pH level.
– Can you use baking soda to lower pH in a hot tub?
Do not try to lower the pH in a hot tub by adding baking soda to the hot tub. Baking soda will not lower the pH in your hot tub, it will raise the pH.
If the pH in your hot tub is lower than the normal range, you can use baking soda to raise the pH level. For this to work, the total alkalinity of water in your hot tub must be low enough.
– How do I lower the pH in my hot tub without chemicals?
You can lower the pH in your hot tub without chemicals by using vinegar. All you need is to add four cups of vinegar to water and add to your hot tub. Allow circulating the water before you test the pH level. Repeat the process if the pH level is still high. As mentioned earlier, you can either use apple cider vinegar or regular white household vinegar.
– What should be adjusted first, alkalinity or pH?
In general, the alkalinity should be adjusted first before the pH. The reason for this is that the alkalinity does not drop as fast as the pH level. If you manage to maintain a good alkalinity balance, the pH will easily adjust to the correct level as well.
– Does chlorine raise or lower pH in a hot tub?
Adding chlorine to your hot tub at normal levels will not alter the pH level of the water in your hot tub. However, if you add an excessive amount of chlorine to your hot tub, it will lower the pH level. When adding chemicals to your hot tub, it is important to ensure that you are adding the correct amount.
– Does pool shock or spa shock raise or lower pH?
A pool shock with calcium hypochlorite will raise the pH level of your pool because chlorine has a high pH level. Also, this type of shock will alter the level of chlorine in your pool. However, the pH of chlorine-free shock is neutral, and this will not alter the pH level or chlorine level of your pool.