Maintaining Your Water Chemistry


After filling your pool, use the following steps to keep the water balanced and clear:

NOTE: Since most concrete/gunite pools are surface finished with a plaster mixture, and since these materials (plaster and concrete) leach chemicals into the pool water, the pH, alkalinity and chlorine levels will vary more than in a vinyl lined pool.

Always store your pool chemicals out of the reach of children, in a well ventilated dry place. Never store liquids over dry chemicals and always use caution when handling pool chemicals.

Never inhale the fumes generated by pool chemicals and never introduce pool chemicals into the pool while swimmers are in the pool.

Keep your filter clean so as to maximize water circulation. Always add shock treatment chemicals, dissolving them into a pail of water before introducing them into the pool.

Chemical containers should always be kept closed when not in use, and never mix chemicals together.

Use separate measuring cups, and never smoke or use open flames when using chemicals.

Do not add chemicals through the skimmer when an automatic chlorinator is in use as trapped gases may cause a violent reaction.

Read all chemical instructions on the label carefully, and follow instructions.

The intent of the following is meant to be used as a guide to point you in the ‘right direction’ toward a chemically-balanced pool.

Step 1

The key to proper water balance is to keep your pH level between 7.4 and 7.6; your alkalinity level between 80 and 120ppm for concrete/gunite pools and 125 to 150 for vinyl lined pools, and your chlorine level between 1ppm and 1.5ppm.

That said, the art of keeping pool water chemistry balanced is sometimes tricky. We’ve all heard of acid rain, well, pool chemistry can change every time it rains or every time more than just a few swimmers use the pool.

In any event, purchase a good 4-way test kit. Follow the instructions and adjust the alkalinity as your first step. Use about 1.5 pounds per 10,000 gallons.

The base chemical used in this product is sodium bicarbonate. Both the 4-way test kit and the Alkalinity Increaser is available through our web site at very competitive prices, or at most pool supply stores, usually at higher prices.

To reduce alkalinity, use acid. We suggest that you lower your total alkalinity slowly in at least two steps, allowing the water to circulate, taking another test and if necessary, adding more dry acid.

Total alkalinity readings and pH readings are not the same. The pH reading is similar to a temperature reading on a thermometer that tells what the present temperature is, while the alkalinity reading tells how much heat is required to reach the desired temperature.

Step 2

Waiting several hours after adjusting the total alkalinity will allow the water to circulate sufficiently to get an accurate reading on the next test, the pH.

Too much alkaline content raises your pH, while too much acid lowers your pH reading.

If your pH level is above 7.6 ( too high or too alkaline), two base chemicals used to lower the pH are Muriatic Acid and Sulfamic Acid.

We would suggest a dry granular acid over liquid, as it is more stable, much safer to use and has a much longer shelf life.

Use approx. one pound dry pH decreaser per 10,000 gallons.We only supply a dry pH decreaser, available on this web site.

Water with low pH (excessively acid water) retards the sanitizing action of many types of chlorine. If your pH is below 7.0 on the pH scale you will need to add about 1.5 pounds of alkaline per 10,000 gallons.


Step 3

Shock the pool with calcium hypochlorite (HTH is the most popular and contains 65% calcium hypochlorite) using one pound of HTH for each 10,000 gallons of water in your pool.

Shock treat the pool approximately every two weeks, depending on the number of people using the pool and the temperature. Temperatures above 90 degrees with every day usage should be shocked every 10 days to two weeks.

Pool water gallons can be figured by multiplying length x width x average depth x 7.5. For example, 16’ x 32’ x 4.5’ (3’ to 8’ deep avg. depth 4.5’) pool = approx. 17,000 gallons of water. In the case of a shaped pool, use average widths and average lengths.

Remember, when using chemicals less is always better. Shock treating a pool brings the available level of chlorine up to approx. 10 ppm. This is necessary because with use, the pool will build up chlorimines, which can chemically ‘tie up’ your chlorine. By raising the chlorine level to 10ppm you chemically free up the chlorine to do what it is supposed to do, kill bacteria.

It is generally accepted that one pound of chlorine will raise 10,000 gal to the point where it ‘shocks’ the pool and releases all ‘tied up’ chlorine. Shocking the pool is best done in the evening when the pool is not expected to be used until the next day, when chlorine levels of less than 2.0ppm are achieved


Step 4

Pool Stabilizer is a product (Cyanuric acid) that inhibits the effects of sun light in dissipating the level of chlorine. It will allow your regular doses of chlorine to act more efficiently in killing bacteria, and over the course of using your pool will require the use of less stabilized chlorine.

Stabilizer levels should be no more than 35 to 40ppm. This is one product that you want to be sure to use the proper dose of as too high a level of Cyanuric acid can also chemically ‘tie up’ the chlorine in your pool.

Stabilizer is usually added only once per year and should be checked occasionally.

However, Stabilizer may not be necessary to use every year as it dissipates very slowly. Pool Stabilizer is available for purchase on our web site.

Step 5

In addition to the above instructions, we highly recommend the use of stabilized chlorine tablets or sticks, i.e., Trichloro (active ingredient 89%).

Since the activity of chlorine is dependent upon a balanced pH (lower pH accelerates the loss of chlorine and higher pH slows the microbicidal function), we highly recommend frequent testing for pH levels.

Sticks and tablets of stabilized chlorine are slow dissolving: use one to two ounces per 10,000 gallons per day. Since these are slow dissolving, you’ll probable only have to add these to the pool on a weekly basis.


Step 6

It is recommended that you use a minimum 40% active algicide the morning after you shock treat the pool.

Read the label: many algaecides contain only 10% or 20% active ingredient. These products are generally not as effective.

Treating your pool with a 40% algicide on a regular basis controls the air borne algae which enters your pool on a daily basis.


While the above program sounds somewhat complicated, it should be broken down into several basic steps.

First of all, adjust the total alkalinity, then adjust the pH. The rest of the program can be boiled down into 3 steps: Step 1, shock treat the pool every 2 weeks; Step 2, add the proper dose of a good algicide the following morning; and Step 3, use stabilized chlorine sticks or tablets on a regular basis.