There’s no doubt that a relaxing soak in a hot tub requires clean
† and fresh water. And the only way that this can be achieved other than replacing the water after every use is to test the water regularly and balance it accordingly. Testing for total alkalinity is the first step necessary for getting the rest of the levels in balance because of its influence on pH level and sanitizer effectiveness. So if you want to learn how to raise total alkalinity in
hot tubs or the effects of high or low total alkalinity levels, we encourage you to read this article.
What Is Total Alkalinity in Hot Tub Jargon?
Total alkalinity refers to the number of alkaline particles found in the hot tub water. Total alkalinity is measured in parts per million (ppm) with the ideal measurement being between 80 and 120 ppm. Total alkalinity within that range is necessary to neutralize acids. It also plays a key role in preventing pH levels from rapidly fluctuating. You can measure total alkalinity by testing hot tub water samples using liquid reagent kits or paper test strips. This should be done once a week – or possibly more often if the hot tub is getting a lot of use. The results from these tests will let you know whether you need to add chemicals and in what quantities.
The Consequences of Low Total Alkalinity
Low total alkalinity often results in a reduced pH level. As the pH level drops below 7 the water becomes acidic. Acidic water can irritate the skin and eyes as well as cause problems with the hot tub itself. Acidic water can promote the corrosion of metal hot tub parts and cause etching and staining of the hot tub surfaces. Chlorine-based sanitizers also become much less effective in acidic water. Low total alkalinity can also cause a phenomenon known as pH bounce where the pH level becomes difficult to control.
How to Raise Total Alkalinity in Hot Tubs?
To prevent the consequences related to low total alkalinity it’s necessary to use a total alkalinity increaser to get it back into the desired range. These increasers are most often composed of sodium bicarbonate, which is also the main ingredient in baking soda. Your water test results will be able to tell you how much you should add depending on the size of your hot tub.
The Consequences of High Total Alkalinity
Hot tub water’s total alkalinity often gets boosted by the presence of sweat, body oils, soaps, and beauty product residues. It may also be a result of a hard water source being used to fill the hot tub. When the total alkalinity levels become too high the water usually becomes murky or cloudy due to the crystallization of dissolved solids. Allowed to continue, this could result in scaling, crystal buildups, and in extreme cases, the clogging of drains and pipes.
How to Lower Total Alkalinity in Hot Tubs?
Similar to the process of treating low total alkalinity, adding a total alkalinity decreaser will bring total alkalinity levels back into the accepted range. These decreasers are often composed of muriatic acid or dry acid, the common name for sodium bisulfate. Because total alkalinity decreasers may also reduce the pH level of the hot tub water, it’s important to monitor both these levels when using these additives.
Now that you’ve learned more about water chemistry and how to raise total alkalinity in hot tubs, download a free buyer’s guide below to get more information, or visit us at our
London hot tub store.