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Alkalinity and pH - The Importance of Being Balanced

The Importance of Being Balanced  

A Simple Guide to Achieving and Maintaining Correct Alkalinity and pH levels in Your Hot Tub Water

 Suffering from green water in your hot tub? Itchy skin or burning eyes? Sounds like your hot tub water is not balanced properly. Balancing the Alkalinity and pH in your hot tub/spa water is very important, not just for you but also for the hot tub itself. Poorly balanced water can result in damage and a shorter life for hot tub equipment such as heaters and pumps and these parts can be expensive to replace. Unbalanced hot tub water can also damage the surface itself and cause cracking or in extreme case osmosis!

 Take a look at our ‘how to guide’ below and find out how to successfully balance your hot tub water.

 All You Need to Know

 What’s the Difference between Total Alkalinity (TA) and pH?

Total alkalinity (TA) is a measure of the concentration of alkaline substances in the water, that is, how much of that substance is in your water.

 pH (which stands for ‘power of hydrogen – who knew?!), on the other hand, is the scale by which you can measure the acidity or alkalinity (often referred to as “hardness”) of your water.

 It is also useful to know that alkaline substances buffer the pH in the water by neutralizing acids. This is why it is better to get your TA levels within the correct range first, then it will be easier to adjust your pH.

Understanding Alkalinity  

 An alkalinity level that is either too high or too low can lead to dry and irritated skin and eyes. In addition, it can adversely affect the surfaces and pipework, thereby shortening the life of your hot tub. Both high and low alkalinity can cause water to turn green.

 Low alkalinity can also cause pH levels to fluctuate wildly, as well as causing damage to your hot tub surface and to the metal parts and pipework. And because low alkaline water is unable to balance the phosphates that feed algae, your water can turn green.

 High calcium levels, cloudy water and scale build-up are the result of high TA. It can also cause your water to turn green due because high TA reduces the effect of chlorine used to control algae.  High alkalinity also makes it difficult to lower high pH levels.

 You can test your hot tub water with either test strips, such as AquaChek 4 in 1 Test Strips, or a digital meter, such as Aquachek TruTest Digital water tester. The ideal TA range for a hot tub is between 80 ppm and 120 ppm.

 If you need to raise the alkalinity, it is advisable to use a product especially made for the warmer water temperatures of hot tubs. One such product is Spa Life Buffer – Alkalinity Plus/Alka Rise. Lower your hot tub’s alkalinity level with Spa Life pH Minus.

 Once you have your alkalinity levels in check, it will be easier to adjust the pH.


For the sake of bather comfort, and to ensure the smooth working and long life of your hot tub,  it is important to maintain a neutral pH in the range of 7.0 to 7.2. Cloudiness and scale caused by either high or low pH lead to problems such as corrosion and bacteria growth.

 Check your pH levels using either test strips such AquaChek 4 in 1 Test Strips, or a digital meter like Aquachek TruTest Digital.

If your pH is low (less than 7.0) it means your water is too acid, and you are likely to experience skin and eye irritation and general bather discomfort. Low pH can also affect the efficiency of your sanitizer (chlorine/bromine), which in turn can lead to exposure to bacteria like pseudomonas. Acidic water causes metal corrosion and can also cause a reduction in alkalinity.

 If your test result shows a pH above 7.2, your pH level is too high, which means your water is too alkaline and you could suffer skin and eye irritation in the hot tub. Furthermore, it can cause metal stains, cloudy water and, again, leads to poorly sanitized water.

 To reduce the pH level in your hot tub, try a product such as Spa Life pH Minus.

To raise the pH in your hot tub, you could use Spa Life pH Plus.