Water Chemistry

Everything affects your pool chemistry. It’s not hard to keep up once you get to know your pool.

Daily Tests, until you get to know your pool, then you can test twice a week.  Remember to test after a rain and get your pool back into balance as soon as possible.

  • Test pH & Free Chlorine levels using a test kit. Ensure pH is within the 7.2 – 7.6 range.
  • The pool filter should run at least 8 to 10 hours per day.  Set your pool timer or remember to run the pool manually if you don’t have a timer.
  • Make sure your skimmer baskets and pump baskets are empty and clear of leaves or other debris.
  • Chlorine must be added to the pool daily.  Best method is to use an automatic chlorinator so you can adjust the amount of chlorine that goes into your pool.
  • Make sure the unit is full of stabilized tablets and that the dial is set to a level that gives you a good daily chlorine reading depending on how long you run your system.

The maintenance of proper water balance is the single most important factor to maximizing the life an appearance of the liner. Proper pH levels, for example, allow the chemicals to perform their function. Chlorine needs a certain pH level to kill bacteria and algae.

Proper technique is important for water testing.  Be sure to read and follow the written instructions from the chemical manufacturer.

Factor Range In-season test frequency Function
pH 7.2 – 7.6 2 times per week Allows other chemicals to operate properly
Free chlorine residual 1.0 – 1.5/ ppm* 2 times per week Kills bacteria
Total alkalinity 6.0 – 125/ PPM* Weekly Ability of pool to counteract change in pH levels
Cyanuric acid 30 – 75/ PPM* Monthly Stabilizes water chemistry
Calcium hardness 175 – 250/ PPM* Monthly To avoid corrosive conditions in pool systems
* PPM = parts per million

pH Levels

Not only do proper pH levels allow the other chemicals to do their work but it is important to note that low and high levels can cause damage to the liner. Under the right circumstances with pH below 7.0, the liner can actually grow and develop unsightly wrinkles. High pH greatly accelerates the aging process and shortens the life of the liner.


  1. In most areas of the country, the circulating range of 1.0 – 1.5 PPM of chlorine will do the job of killing the bacteria in the water. Above this range high concentrations will attack the liner, bleach it and shorten the life. Below the range might not kill the bacteria causing unsanitary conditions and possible staining.
  2. Never let chlorine come into contact with a liner before it has fully dissolved. This means that granular or tableted chlorine is dissolved first in a bucket of water, and likewise liquid chlorine is poured in various locations around the pool and is immediately agitated, dispersed and circulated. The broadcasting of tablets, granules, or concentrated chemicals can bleach the liner and shorten the life of the liner.
  3. Never mix chemicals together, rather add chemicals to pool water separately and circulate throughout pool before adding second chemical.

Clean the Water Line

Another major contributor to shortening the life of a pool liner is dirt and grime at the water line of the liner. The “bathtub ring” is usually caused by the accumulation of airborne contaminants, combining with the dirt and body and suntan oils to settle on the liner and can be baked into the liner by the sun. If the scum line gets baked in, it acts on the vinyl to prematurely dry and crack it, especially in the “sun corner” of the pool.

There is a simple and inexpensive way to reduce the problem. Routinely wipe the water line with a sponge (or a sponge with a recommended vinyl cleaner) to eliminate grime build up.

If grime build up has occurred, be sure to use only vinyl cleaners recommended by your Pool Dealer.  DO NOT USE GASOLINE, KEROSENE, OR OTHER PETROLEUM PRODUCTS EITHER, AS THEY CAN CAUSE RAPID DETERIORATION OF THE LINER.

Protect the Water Line

A good, non-alcohol, non-petroleum based vinyl protective liquid applied to a clean vinyl surface will reduce grime build up and ultra violet deterioration. Be sure to talk to a Pool Professional. Select a product specially suited for this use.

Don’t Drain the Pool

Never lower the water level of the pool to less than a foot of water in the shallow end. If water pressure is removed from the liner, it may shrink, causing, at the least, an unsightly liner, and up to tearing around fittings or in the corners. DO NOT DRAIN THE POOL, FIRST CALL YOUR POOL PROFESSIONAL.

Weekly Pool Maintenance

  • Completely backwash filter.
  • Check return flow of water to the pool. Add chemicals at this point to ensure effective mixing with filtered water return.
  • Test & adjust water for Chlorine, pH and Alkalinity.
  • Vacuum pool floor and walls or run your automatic pool cleaner.
  • Empty skimmer baskets and pump basket.
  • Check pool ladder, diving board and slide to make sure they are secure.


There are several types of filters available for swimming pool water. Sand and gravel, diatomaceous earth, anthracite, and cartridge types are the filter mediums most commonly employed. Regardless of the medium used, the basic principles are the same. This consists of passing water through tiny passageways. Particles larger than these passages are trapped and thereby separated from the main body of the water. This process continues until all of these passageways are blocked. The filter must then be cleaned and the cycle repeated.


A filter is designed to remove sediment and suspended matter from the main body of water, however, some dirt will inevitably settle to the bottom of the pool during periods when the filter is not in operation. The only way for this sediment to be removed is through vacuuming.
The swimming pool vacuum operates in a similar manner to the common household unit except it draws water through the vacuum head instead of air. There are two ways in which this may be accomplished. One method employs a jet of water supplied by a garden hose to power the suction which draws the dirt into the head to be trapped in a cloth bag. The other method uses the suction power supplied by the filter which draws the sediment and dirt from the pool floor for removal through the filter. When there is a considerable amount of sediment to be removed the filter valves should be adjusted so that the vacuumed water will bypass the filter and run to waste.

It is recommended that the pool be vacuumed about once weekly, the exact schedule to be determined from the pool owners experience.

Surface Skimming

Hair, lint, leaves and insects which enter the pool and remain floating on the surface can be easily removed with surface skimmers. There are two types of surface skimmers-hand and automatic. The hand skimmer is simply a plastic screen or net attached to a long pole and should be used to remove the larger floating objects such as leaves and grass.

The automatic surface skimmer is a device which is attached to the filtering system. During the filtering process, part of the surface water is drawn through the skimmer and into the filter, carrying with it dust, small insects, and other fine debris before these can settle to the pool floor.

The pool should be skimmed frequently since most dirt enters the water through the surface.