pH & Total Alkalinity:
The topics of pH and total alkalinity are inter-related and are key parameters (factors) in the overall pool water chemistry. pH is the relative acidity or alkalinity of the water. The pH scale goes from 0 (most acidic) to 14 (most alkaline) A pH of 7.0 is neutral. Ideally, spas and hot tubs should be maintained in the 7.2-7.8 range for a variety of considerations: sanitizer effectiveness, bather comfort, corrosion, cloudy water and scaling. Total alkalinity is a measurement of the total quantity of alkaline materials present in the water. Low TA allows for rapid pH fluctuations makes pH control more difficult and can contribute to corrosion. High TA makes pH adjustment more difficult and can be a contributing factor in cloudy water and scaling. A TA range of 80-120 PPM is considered optimum. Control of the spa or hot tub water chemistry is necessary to assure optimum pool water quality.
Calcium is a naturally occurring mineral that is frequently found in high concentrations: such water is called “hard” water. Calcium hardness is one of the important spa and hot tub water chemistry parameters and its control is important to help assure proper water quality. Calcium problems do not normally impart a color to the spa water, as does the presence of metals such as iron and copper. The preferred range for spas and hot tubs is 80-200 PPM. Low levels of calcium can lead to possible corrosive water conditions. Chemicals are available to raise the calcium hardness, as might be necessary. High calcium hardness levels, especially above 400 PPM, can lead to possible water clarity problems and scaling conditions. Various chelating or sequestering Mineral Treatment Products are available to help deal with the problems associated with high calcium hardness levels. Spa or hot tub calcium hardness levels can be determined by a simple water analysis. This is especially important with well water, as other problematic minerals might be present and could require treatment. Spa Water Magnetizers, also known as Magnetic Water Conditioners have been reported to help reduce and eliminate scale formation, by inducing a positive electrical charge in the water passing through the return lines.
Mineral content in spa or hot tub water can lead to a variety of problems: staining of the underwater surfaces, discoloration of the water and corrosion. Control of trace minerals and maintaining a proper overall spa or hit tub water chemistry is important, to help assure optimum water quality. Minerals such as iron, manganese and copper are the principal offenders. Iron and manganese can occur naturally in water, especially well water. It is the oxidation of dissolved heavy metals that can cause the spa staining and water discoloration problems, upon the addition of oxidizing spa chemicals. Copper is rarely found in municipal water supplies and usually finds its way into spas and hot tubs as the result of corrosion of the copper heater core or copper plumbing. Treatment of the resultant problem is usually possible with the proper techniques and chemicals.
Spa Water Testing:
Proper water management starts with the analysis and balancing of the spa or hot tub water. Tests such as pH and sanitizer need to be performed by the spa owner, on a frequent or daily basis, depending upon the sanitizer choice and usage conditions. If Chlorine is used, it should be tested by a method that measures Free Chlorine, as it is the most important. Tests such as total alkalinity and calcium hardness are performed occasionally and can be done by a spa owner or dealer. Tests for heavy metals such as iron, manganese or copper should be performed at the initial filling or at the first indications of spa water discoloration or a spa surfaces staining problem. These tests are usually performed by a spa professional. Maintaining or balancing proper spa or hot tub water chemistry is important to help assure optimum water quality and to maximize the “hot water” experience.