Do you know how to raise alkalinity without raising pH in hot tub? If you don’t, then I will explain the process of doing just that in this guide.
As relaxing as they may be, hot tubs can be rather difficult to maintain at times. More importantly, one has to make sure that they maintain the correct level of alkalinity in their hot tub’s water.
Otherwise, it could start having negative effects on your hot tub. You can check the alkalinity of your tub using test strips that will let you know if the alkalinity is too high or too low.
If a low alkalinity in your hot tub is the issue, look no further because we’ve got some helpful tips to help you get your hot tub balanced once again.
Total alkalinity refers to how buffered the water in your hot tub is against any sudden changes to the pH. Ideally, your hot tub’s alkalinity level should be between 80 to 120 ppm, or parts per million.
Total alkalinity also signifies the concentration of hydroxides, carbonates, bicarbonates, as well as other alkaloids within your sample.
How To Raise Alkalinity Without Raising pH In Hot Tub
If you’ve tested the water in your hot tub and have come to the conclusion that you do in fact need to raise the alkalinity, there are a few things you can do.
The first thing would be to increase your hot tub’s alkalinity level using sodium bicarbonate, otherwise known as baking soda.
Typically, one tablespoon of baking soda per one hundred gallons of water in your hot tub should do the trick.
Obviously the bigger the hot tub, the more baking soda you’re going to need. Once you’ve added the baking soda in, let it sit and soak up before you test it again.
You also have the option of using an alkalinity increaser product to help raise the alkalinity in your hot tub. If you do go this route, however, be sure that the product’s main ingredient is sodium bicarbonate.
There isn’t really much of a difference between the two other than the name.
What Happens When You Have Low Alkalinity in Your Hot Tub?
Having a low alkalinity in your tub can be extremely damaging and its effects might not be immediately noticeable.
However, a low alkalinity level in your hot tub will often drive the pH level in the hot tub down, which in turn makes the hot tub water more acidic.
When dealing with acidic water, you’ll see the effects on your body such as itchy dry skin and irritated eyes.
Other common issues associated with having low alkalinity in your hot tub include the pitting, etching, cracking, and delamination of the walls and surfaces of said hot tub.
There will also be corrosion of any metal surfaces near the hot tub, a fluctuation in the water’s pH balance, and you could even risk having an unsanitized tub because low alkalinity can affect how chlorine works in the tub.
As a result, the water in your hot tub could end up with an unappetizing green tinge.
What Happens When You Have High Alkalinity in Your Hot Tub?
Low alkaline levels in your hot tub are certainly the worse of the two, but there are also some disadvantages to having the water in your hot tub be high in alkalinity.
For instance, one of the issues that you might have is seeing cloudy or murky water and clogged filters. The reason for this is that particles in your hot tub will start to float more freely.
When your filters are clogged, your pumps also become clogged and therefore are forced to work harder. The water pressure begins to increase thus causing cracks that will result in you having to replace them all together.
Worst of all, you could end up experiencing pH lock, which happens when the hot tub water’s pH is resisted as a result of the high alkaline levels in the hot tub.
Lowering the Alkalinity
In this case, your best bet would be to use muriatic acid and sodium bisulfate or an alkalinity decreasing product.
Once you’ve added in these ingredients, be sure to let your hot tub jets run for a couple of hours while the product sets in. After enough time has passed, be sure to check the pH level in the hot tub, as the pH level may have also dropped.
Be sure that after adding any sort of chemical to your hot tub you are also keeping your tub’s cover off to allow the water in the tub to breathe as well as to allow the chemicals to circulate and release any odors into the air.
Balancing Your Hot Tub’s pH
The alkalinity of your hot tub isn’t the only thing that matters. Your hot tub’s pH levels should also be balanced. To find out if the pH levels in your hot tub are too high or too low, you will first need to test the water using test strips or a liquid test kit.
Your hot tub’s pH levels should ideally be between 7.4 and 7.6. If your test results show that your hot tub water is anywhere outside of that, you may have some problems on your hands.
When your tub’s pH levels are too low, it means that the water is too acidic. The more acidic your hot tub is, the less likely your water sanitizer will work.
As a result, it could leave you or anyone else who uses the tub at risk for being exposed to potentially harmful contaminants. If the pH levels are too high, your water is considered basic and will also be at risk for being highly unsanitary.
Basic water can also cause your tub to form scales all around it as a result of hardness caused by the high pH levels. Balancing your hot tub’s pH levels is quite simple and only requires certain types of pH increaser or pH decreaser.
If you’re having a hard time getting the water in your tub to balance and you’ve tried just about everything, your best bet may be to drain the water and start over.

Hello, my name is David Zal and I’m a plumber with more than 20 years of experience based in Englewood (Florida). I like to teach normal people how to make easy fixes in their homes. I believe that a lot can be achieved just with DYI and that’s why I started this blog.