Does Vinegar Lower Alkalinity In A Hot Tub?

Vinegar is not just a popular naturally derived substance but also a regular name in hot tub care. It is cheap and easy to get, and I’m quite sure you have come across it more than once.

Vinegar does not lower alkalinity. Instead, what vinegar does is lower the pH of the hot tub water.

So if vinegar does not lower alkalinity, how do you go about lowering the alkalinity of your hot tub water?

To lower alkalinity, you need to apply a pH decreaser or soda ash, also known as sodium bisulfate. Muriatic acid is another popular chemical for lowering alkalinity.

What does adding vinegar to a hot tub do?

Keeping the pH level of your hot tub at the appropriate level is a necessary part of spa maintenance. 

You can purchase products from a pool supply store to regulate the pH, but if you do not have these chemicals on hand or if you prefer a more natural approach, adding vinegar to your spa can safely lower the pH.

Does vinegar cause harm to hot tubs?

Vinegar does not cause harm to your hot tub. Made from grain and water, it is perfectly safe to use in a hot tub. It is a weak acid, so it is not particularly popular for balancing pH or total alkalinity, even though it can lower pH slightly. 

Rather, vinegar is mostly used for cleaning purposes. So you can use vinegar as a cheap and effective substance for cleaning your hot tub. To avoid color stains, it is advisable to use white vinegar.

How much vinegar should I put in my hot tub?

If you are looking to clean your hot tub and also lower your hot tub pH. Add a gallon or four cups of vinegar, preferably white or apple cider vinegar to avoid coloring, to your hot tub.

Now run your hot tub to properly mix and circulate the vinegar for about an hour or more. Running through the jets is going to help in cleaning them while also dropping the hot tub pH.

To clean the hot tub surface, just pour undiluted vinegar onto a cleaning cloth or sponge. Use it and swipe the inside of your hot tub. Rinse it off with warm water after allowing it to sit for about 5 minutes.

What is the difference between pH and Alkalinity?

Very frequently mentioned in hot tub care are the terms pH and alkalinity. Most often, this is a cause of confusion as to what is responsible for what defects in the chemical balance of hot tub water. 

A major mistake most people make is thinking they are opposite terms, just like high and low. But the fact is, they are two separate and different terms that affect one another. 

And while you are trying to adjust one to an ideal level, the other might drop or increase. This is why it is very important to know what is what and how to adjust what without negatively altering the other.

pH means the power of hydrogen. It is a measure used to determine how acidic or basic the water in your hot tub is on a scale of 1 to 14.

With 7 being the value for pure and neutral water, going up or down the scale is interpreted as increasing acidic or alkaline levels. The value of 0 shows the highest acid level, while 14 represents the highest alkaline level

The upper half of the scale, alkaline, is what most people misunderstand as alkalinity. Alike as they might seem, but different. So then what is alkalinity?

Alkalinity is most often referred to as total alkalinity and is shortened as TA. it represents how effective your hot tub is at resisting changes in its pH, a buffer solution per se neutralizing acids. 

Furthermore, it is a measure of the number of alkaline substances in a solution. Unlike pH, which has a scale of 0-14, alkalinity is measured in parts per million (ppm). 

So the alkalinity of the water in your hot tub will give you an idea of the amount of carbonate, bicarbonate, and/or hydroxides present in your hot tub. 

These compounds are what act as acid neutralizers in your hot tub. Hence, alkalinity is very important for maintaining ideal pH levels.

The ideal pH for a hot tub is between 7.2 and 7.4. The idea here is to keep it as close to the pH of the human body as possible, and that is slightly basic. Anything outside that range tends to have noticeable effects on the human body.

On the other hand, the ideal total alkalinity level falls between 80 and 120 ppm. It is important to note that where you adjust your total alkalinity within this range depends on the type of alkaline substances you are using. 

Whether it has a low pH, a high pH, or a very high pH. For instance, chlorine, which is popular for adjusting alkalinity, comes in different kinds, each with varying pH strengths. 

Trichlor is chlorine with a low pH. Using it ideally, you should adjust your total alkalinity to be near the upper range of 120 ppm as possible. 

Despite being weakly alkaline, at such a high concentration, it will be able to resist strong acids. In the same way, keep high pH chlorine at the near bottom range of the TA scale, between 80-120 ppm.

With so many ideal ranges, maintaining a good hot tub chemical balance now seems very complex. Don’t worry, there is always an easier way to work these things out. Which brings us to the next question that might probably cross your mind: what to adjust first, pH or alkalinity?

How can I lower Alkalinity without lowering pH?

Both TA and pH levels, though serving different purposes, go hand in hand. Adjusting one usually tends to affect changes in the other. 

This might be a good thing and also a bad thing, depending on the chemical balance of your hot tub before treating. Let’s say your hot tub pH level is at an ideal point but the total alkalinity is not. 

So how do you adjust one without affecting the other? In this case, how do you lower alkalinity without in turn lowering the pH of your hot tub?

Reducing alkalinity without lowering the pH level is going to be nearly impossible. The reason is that doing this requires the addition of acids, which, as you know, will have a reducing effect on the pH level. 

The trick here is to forget about the pH level first and adjust the alkalinity. After that, the pH level is adjusted with minimal effect on alkalinity. This is usually referred to as the “two-step” process.

So, using the two-step process, you are going to adjust the alkalinity first by adding an acid. The most commonly used one for doing this is muriatic acid

Add it until you lower your hot tub‘s total alkalinity to an acceptable level. Remember the ideal level mentioned above, it should be something within that range.

After lowering the alkalinity to the desired ideal level, the next step is to adjust the pH. As a result of the addition of acids, the pH is probably going to be below the ideal range now. 

Adding alkaline substances in a bid to increase the pH might alter the total alkalinity balance. So your best bet for increasing pH to the ideal level is by aerating the hot tub. 

This will bring the pH back to the ideal level without increasing the alkalinity. Run your pump and jets at full blast with the hot tub cover lifted to create as much surface disturbance as possible. 

The more the surface is disturbed, the quicker you will get your pH level back to normal.

A very important safety precaution to note while doing this is to never mix acids. Use just one. Also be sure to dilute the acid in a bucket of water before applying it to avoid damage to your hot tub lining as a result of direct contact. Ensure you apply the mixture evenly at different points to ensure an even effect.

What does high Alkalinity do to a hot tub?

You are probably wondering why it is important for you to lower the alkalinity level when it is high. Well, high alkalinity will cause the following in your hot tub:

  • The effectiveness of sanitizers will be low when the alkalinity of your hot tub is high. This can cause the water to turn greenish as a result of organisms growing on the linings. Also, you need to apply more than the usual amount of sanitizers to see any effect. And this, as you know, will bring more expenses and make your hot tub chemically laden.
  • When alkalinity is high, adjusting pH is very difficult. This is because it tends to neutralize everything acidic immediately. And while high acidic levels are harmful, very low acid levels are not friendly either.

What causes high Alkalinity in a Hot Tub?

Though not a frequent issue with hot tubs, it is possible to have high alkalinity hot tub water. The causes of high alkalinity in your hot tub can be any of the following reasons.

  • Error. Yes, it is very much possible that you are the one responsible for increasing the alkalinity of your hot tub. Though it might be by mistake, while adding alkalinity increaser you could have added way too much.
  • Body fluids and ointments from hot tub users. Sweat, lotions, hair creams, and other ointments applied to the skin and hair have different levels of acidity. With each soak, they can gradually cause changes in alkalinity.
  • Water sources also contribute to high alkalinity. If the source of water for your hot tub has high alkalinity, well, do the little math, your hot tub water will be high in alkalinity too.
  • Accumulated chemicals. When you keep on adding chemicals from time to time in a bid to maintain a balanced chemical level for your hot tub, the level of total dissolved substance, shortened as TDS, will also be increased. At this point, treatments will be less and less effective, and alkalinity levels will be high.

How to prevent high alkalinity in a hot tub

Any of the above can be the reason why your hot tub pH is high. High alkalinity can be prevented with simple actions like,

  • Draining and cleaning your hot tub regularly, say every 3 months. This will prevent the accumulation of chemicals over time.
  • Have a shower before going for a soak. Especially on hot days when people sweat a lot. This way, you won’t be dissolving your body fluids in the water every time you soak.
  • Check the water reading of your water source to ensure it is not high in alkalinity. Most public water suppliers usually add some chemical treatments to the water.
  • Ensuring you know the right amount of chemicals to add to your hot tub water. Most chemicals have prescriptions written on the body, so check before you use them, or ask when you are not sure.

Regular cleaning is the best way to keep your hot tub water in good and healthy shape. Draining and cleaning your hot tub regularly will stop chemical buildup and keep your hot tub water clean and healthy.

Does Baking Soda Lower Alkalinity in a Hot tub?

Baking soda, also known as sodium bicarbonate, does not lower alkalinity. When added to hot tub water, it increases the alkalinity instead. So if you are looking to reduce your hot tub’s alkalinity, adding baking soda is a big no-no.

Aside from increasing the alkalinity of a hot tub, baking soda also raises the pH level. So you can use baking soda to correct your pH from a low level after adjusting the alkalinity. 

It is never a good idea to use baking soda to increase pH when alkalinity is high. This is because it can cause green water. So it is best practice to adjust your alkalinity first before considering pH levels.

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