pH and Total Alkilinity

pH and Alkalinity are one of the most common areas of confusion for many hot tub users and the risks associated with unbalanced water can damage your hot tub so it is a very important to get right. Questions such as “what is the difference between alkalinity and PH?”, “Why does PH matter in my hot tub?” and “How do I raise alkalinity in my hot tub?” are the most common and will be answered below. 

What is Total Alkalinity?

Total alkalinity (TA) is the measure of the capacity of water to neutralise acids. It is different to PH. It is measured by parts per million rather than a scale like pH. Alkalinity is important as it acts as a buffer when balancing pH. If your alkalinity is out, then it will be very hard to balance your pH level. In fact it is a good idea to balance your Alkalinity before doing anything else as this may allow your pH to fall into line too and will make balancing pH much easier. Your Alkalinity level should be between 80-120ppm.

What is PH and Why is it Important?

So once you have balanced your TA, the next step is to use a test kit or strips to check your pH level. pH is the measure of how acidic or how alkaline your water is. 7 is the neutral pH level but in your hot tub you want to aim to get your PH between 7.2 and 7.8. If you do not do this you may in for some nasty and potentially costly surprises!

Potential Issues with Low pH:

  • Poor Sanitiser Efficiency. Using lots of chlorine to not much effect and adding risk to bathers.
  • Corrosion of hot tub components due to the acidic nature of the water.
  • Itchy dry skin and eye sting.

Potential Issues with High PH:

  • Poor Sanitiser Efficiency. Using lots of chlorine to not much effect and adding risk to bathers.
  • Scale build-up on the spa surface and on components.
  • Cloudy or dull water and foaming.

How to Balance pH & Alkalinity

Balancing your pH and Alkalinity follows the same concept for both. If your levels are low, add increaser, if your levels are high, add reducer! The only difference is what chemicals you need to use. 

Lowering PH & Alkalinity Levels

If your PH and/or Alkalinity is high, you need to add a pH Minus to reduce these levels.

  • Do this gradually. Add the correct dose of pH Reducer, then run the jets and re-test in an hour or so and see if you need to reduce further.
  • pH Minus is the sole chemical used to reduce pH and Total Alkalinity in your hot tub. 

Raising pH Level

If your pH is low, you need to add a pH Plus to increase these levels.

  • Do this gradually. Add the correct dose of pH Increaser, then run the jets and re-test in an hour or so and see if you need to reduce further.
  • pH Plus will increase your Alkalinity level slightly too so keep an eye on this as remember Total Alkalinity is the buffer to allow your PH to be set.

Raising Total Alkalinity Levels

If your TA is low, it is most effective to use TA Plus to increase this level. PH Plus will increase your TA as mentioned above, but it will do so at a slower rate.

  • As with all other adjustments, remember to do this gradually so that you don’t increase TA levels too high resulting in the need to bring these down again.