Water Chemistry and Treatment Guide

pH
Chlorine
Alkalinity
Cyanuric Acid
How do I test?

pH

pH is a measure of how acidic or basic a liquid is. A pH greater than 7.0 is basic, and a pH lower than 7.0 is acidic. The acceptable pH level for pools and spas is between 7.2 to 7.8 for residential pools. The National Spa and Pool Institute (NSPI), the industry association in the United States, has set a standard of 7.2 to 7.6 as the ideal pH. If the pH level of your pool or spa is off, first check the Alkalinity level and make any necessary adjustment to the Alkalinity level before you adjust the pH. This will prevent sudden fluctuation of pH level.

Raising pH with Soda Ash (Sodium Carbonate)

What happens if pH is too low?
- The water can corrode surfaces, metal equipment or fixtures.
- Swimmers and bathers can experience discomfort from burning eyes and itchy skin.
- The chlorine may dissipate more quickly.
- The water may cause pitting and etching of plaster surfaces

Lowering pH with Dry Acid (Sodium Bisulfate)

What happens if pH is too high?
- Calcium and metals tend to come out of solution (the opposite of dissolving) at high pH levels, creating the potential for staining and scale formation. The calcium and metals will actually create deposits and discoloration on pool walls and equipment.
- Swimmers and bathers can experience discomfort from burning eyes and itchy skin.
- High pH can contribute to cloudy water.

Chlorine

There are two indicators for chlorine level in pools or spas: Free chlorine and Total Chlorine. Free chlorine indicates the active chlorine available in the water to to keep water sanitized. Total Chlorine indicates the chlorine in the pool that has been used to sanitize the pool. Too much Total Chlorine can cause eye irritation. Make sure you keep proper Free Chlorine level in you pool/spa water. pH and Alkalinity must be adjusted to proper ranges before adjusting chlorine level.

Chlorination Chart - Pools (amount required to raise chlorine level by 1 ppm)

Super Chlorination Chart - Pools (amount required to raise chlorine level by 10 ppm)

Chlorination Chart - Spa (amount required to raise chlorine level by 4 ppm)

Super Chlorination Chart - Spa (amount required to raise chlorine level by 10 ppm)

Alkalinity

Alkalinity is a measure of total alkaline substances in your pool/spa water. Proper level of Alkalinity in the water protects against sudden fluctuation in pH level. Alkalinity level should be adjusted before pH or chlorine level adjustment is made.

Raising Alkalinity with Sodium Bicarbonate

Lowering Alkalinity with Dry Acid (Sodium Bisulfate)

Cyanuric Acid (Stabilizer or Conditioner)

Cyanuric acid (stabilizer or conditioner) reduces loss of chlorine to the sun's ultraviolet rays. Chlorine in water without sufficient level of Cyanuric acid will not last long and you'll be loosing chlorine in to the air. Dichlor and Trichlor chorines already come with stabilizer added in them. If you're using liquid chlorine you'll need to add stabilizer. Too much Cyanuric acid will cause reduced chlorine efficiency and contribute to scale, stains and cloudy water.

How do I test?

The easiest way to test for pH, Free Chlorine, Alkalinity and Cyanuric Acid levels in residential pools is to use Aquachk® Yellow test strips.

AquaChek Pool and Spa Test strips: Test for: - Free Chlorine - Total Alkalinity - pH - Stabilizer Quick 15 second pool test!

$7.95

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