Swim World Pools

Pool Chemistry Basics

Pool Water

A study at Harvard University concluded that one active adult swimmer loses two pints of perspiration per hour. Perspiration is loaded with organics resembling the chemistry of urine.
The body is also constantly shedding microscopic skin particles sloughed off by the friction of water. These are all “involuntary wastes” such as expectorant, nasal discharge, fecal matter and urine and you begin to appreciate the bather load created.
Four bathers in a 7 – foot 600 hundred gallon spa is the equivalent to 250 bathers in a 25’x 50’x 4′ swimming pool. That is NOT a very big pool for that many people!
Alkalinity (Always adjust Total Alkalinity first) 80 – 120 ppm.
The alkalinity of your pool has to do with the ability of the water to resist change in pH. The alkalinity helps manage or control the pH. It acts as a buffer.
Many of you may have heard the term pH bounce. This is typically caused by out of balance alkalinity levels. Keep your alkalinity level between 80 – 140.
If you have a salt – water pool or use Tri – Chlorine tablets keep the alkalinity between 120 – 140. If you use Sodium Di – chlor keep the alkalinity between 100 – 120 ppm.
If you are using Liquid Chlorine, Cal-Hypo or Lithium Hypo keep the alkalinity in the 80 – 100 ppm range. When alkalinity is lower than 80 ppm it becomes aggressive and the pH can easily swing up or down.
When alkalinity is on the high side above 140 the water can become clouded and scale forming. In most cases if the pH is high the alkalinity will be as well. If the alkalinity is low or high it is likely that the pH is affected similarly. Alkalinity can be adjusted with some of the same products you would use to adjust pH.
Always add chemicals in smaller increments. Do not add more than 1 pint at a time. Keep the pool circulating and wait for a few hours and then retest your water. Make another adjustment if necessary.
In some cases it may take several attempts to get it right. Never mix water with acid first. Always add acid to water. Be careful and cautious at all times.
Always test you water before adding any chemicals. ALWAYS read manufacturers labels.