Total Alkalinity in Spas & Hot Tubs

Total Alkalinity in Spas & Hot Tubs

Total alkalinity is the measure of the amount of alkaline buffers (primarily carbonates and bicarbonates) in your water. These alkaline substances buffer the water against sudden changes in pH. Total alkalinity is considered the key to water balance. It is the first parameter you should balance when making routine adjustments to your water.

If you neglect to check the total alkalinity in your pool or spa, you may have trouble balancing the pH. You may also notice that pH fluctuates suddenly despite your best efforts to keep it in the ideal range. If the alkalinity is too low, anything introduced to the water will have an immediate impact on pH. Abrupt shifts in pH can cause scaling or corrosion of metal equipment and fixtures as well as other problems. When the total alkalinity is high, the pH has a tendency to drift upward, causing scale to form.

Maintaining an ideal level of alkalinity will protect your pool or spa and its equipment from the harmful effects of sudden pH fluctuations. Think of the alkalinity as training wheels: it keeps the pH in balance without allowing it to tip too far to either side. Of course the pH can still drift upward or downward, but that change will happen gradually as long as the alkalinity falls within the ideal range. The ideal range of total alkalinity spas is between 80 and 160 ppm.
 

Adjusting the Total Alkalinity (TA)

It is pointless worrying about your pH or Calcium Harness level until you have got the Total Alkalinity to within the correct range, so  always start here. 

You should maintain total alkalinity levels within the ranges shown in the table.