Water Balance

Written by James Panico.

Spa Water Balance

Water balance has five factors: pH, Total Alkalinity “TA”, Calcium Hardness “CH”, Temperature, and Total Dissolved Solids “TDS”. For our purpose, it is assumed that the temperature will stay between 35 C and 40 C, and the TDS level will remain below 1500 parts per million (ppm), providing the drain and refill schedule is followed.

Water balance affects the safety of your equipment as well as the appearance of the water. pH is most critical, but the TA and CH levels must also be considered.


Maintain pH between 7.4 and 7.8. Spa Life pH Up raises pH; Spa Life pH Minus lowers pH. See the above table.

NOTE: Dosages will vary depending on TA and CH levels. The recommended dosages are approximate and presume the water is balanced to 100 ppm TA and 250 ppm CH. All dosages per 2000 litres (Tbsp. = level tablespoon).

Total Alkalinity

Total Alkalinity buffers or controls changes in pH. Maintain TA between 100-150 ppm. Total Alkalinity is critical to the protection of the equipment. Spa Life Buffer, in four level tablespoon doses, will raise the TA 20 ppm in 2400 litres of water.

Calcium Hardness

Calcium Hardness controls overall buffering capacity of the water. Low CH can lead to corrosion; high CH to scaling, cloudy water and staining. Maintain CH between 150-300 ppm. 10 level tablespoons of Spa Life Cal will raise CH 50 ppm in 2000 litres of water. To lower CH, drain part of the old water, refill with fresh tap water, then retest.


Lawrason's, Inc. 460 Wyecroft Road, Oakville, ON  L6K 2G7

Tel: 905-842-8300   |   Fax: 905-842-8906   |   E-mail: