Proper water balance is the single most important factor to maximizing the life and appearance of any swimming pool. The following table shows ranges for basic water chemistry.

pH7.2 - 7.6Daily
Free Chlorine1.0 - 2.0Daily
Total Alkalinity80 - 120 PPMWeekly
Calcium Hardness200 -300 PPMMonthly
Stabilizer35 - 60 PPMMonthly

pH Levels

pH is the measurement of acidity of water, which is measured on a scale of 0 to 14 with 7 being neutral. A pH below 7.0 means the water is very acidic, as the pH approaches 8.0, the water becomes very basic (alkaline).

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 a vinyl 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.

Chlorine is much less effective at higher pH levels. Eat a pH of 8.0, chlorine is only 22% effective.

Total Alkalinity

Alkalinity is a measuring of the alkaline materials dissolved in water. With the alkalinity in the range of 100 to 150 PPM it helps pH to resist fluctuations. If the alkalinity is low the result is "pH bounce" in and out of range.

Calcium Hardness

Calcium hardness refers to the amount of dissolved minerals in water. A low hardness can lead to corrosion of pool surface, filter, heater, ladder, etc. A calcium hardness level that is too high causes cloudy water and scaling (white chalky appearance).

Out of Balance Water

  • Eye and skin irritation
  • Staining
  • Unsightly wrinkles in vinyl liners
  • Interferes with the efficiency of sanitizers
  • Corrosion of metals (pump seals, heaters, lights, etc.)
  • Cloudy water
  • Scale build up (white chalky appearance) on pool surface as well as inside filter and heater
  • Pitting and corrosion of gunite/concrete pools

Cloudy Water

The murky, dull appearance of cloudy water can leave the pool looking uninviting. Cloudy water may also harbor contaminants and stain-makers.

Causes of Cloudy Water

Contaminants buildup: When swimmer wastes and other contaminants build up, the result is "combined chlorine." Shock the pool!

Chemical residue: using a calcium hypochlorite shock such as Shock, Sock-It, Shock-it, Burn Out, or Break Out can result in a residue build up and cloudy water. If the water looks like chalk or milk, it is usually the result of using a lot of calcium hypochlorite shock. To use this type of shock, especially in vinyl liner pools to prevent bleaching of the liner, you must:

  • Fill a bucket about 1/2 full of water
  • Add shock. Do not stir. Let sit for a few minutes. Pour only the liquid into the pool.
  • Discard the residue
  • Do not try to dissolve the residue

Water Out of Balance: A high pH, high total alkaline, or high calcium hardness will cause cloudy water. Test the water!

Algae: Algae is a possible cause of cloudy water.

Poor Filtration: Is the filter system running a significant number of hours every day? During the swim season, the filter needs to run a minimum of 10 to 12 hours daily.

Pools with cloudy water or algae:

  • Adjust pH to 7.2 -7.6
  • Add algaecide 60
  • Add shock
  • Add Hydrofloc
  • Add Majestic Blue
  • Run filter 1 hour, turn off and leave off overnight
  • Next day: vacuum the waste

Metals: The presence of metals in the water such as iron (reddish-brown), copper (blue-green) or manganese (brown-red) can cause cloudy water. To remove the metals:

  • Add 1 quart Hydrofloc
  • Add 1 quart Majestic Blue
  • Run filter 1 hour, turn off overnight
  • Vacuum the waste
  • When pool is completely clear, add Keetrol (stain and scale preventer) to remove any stains
  • Use Keetrol weekly to prevent recurrence

Adding Water Balance Adjustment Chemicals

It is best to predissolve a water balance adjustment chemical in a plastic bucket of pool water. Then add to the deep end of the pool or in front of a return with the pump running.

  • pH Adjustment: Add recommended dosage, wait several hours and test water again.
  • Alkalinity: Add at the rate of 5 lbs or less; wait about 10 minutes between each 5 lbs.
  • Hardness: Add at the rate of 5 lbs. Or less; wait 30 minutes between each 5. If large amounts of calcium are needed, add over several days.

Low pH and High AlkalinityAdjust Alk first - Next Day pH
High pH Low AlkalinityAdjust pH first - Next Day Alk
Low pH and Low AlkalinityAdjust pH first - Next Day Alk
High pH High AlkalinityAdjust Alk first - Next Day pH

Chlorine Stabilizer (100% Cyanuric Acid)

Stabilizer acts as a sun shield to extend the life of chlorine up to 3 1/2 times. It actually holds the useful form of chlorine in the pool water until needed giving longer protection against bacteria and algae. It leaves no residue; it is 100% soluble. "Stabilized" chlorine products (sticks, tablets, and chlorine powder) contain some cyanuric acid which helps to maintain the proper level throughout the season.

Adding Stabilizer

With a clean pool, backwash the filter. Make a slurry of stabilizer and water, then add very slowly through the skimmer with the pump running continuously for at least 48 hours. Do not backwash for 3 or 4 days after adding stabilizer.

Pool Maintenance

Testing the Water

  • Follow test kit instructions (test strips are easier to use than kits)
  • Use fresh reagents--the shelf life for liquid reagents is only one year
  • Rinse out test cell with pool water before using.
  • Retrieve water sample at elbow depth from deep end of the pool

Most Important Pool Side Tests: Free chlorine, pH, and total alkalinity. Free chlorine is the unused, effective chlorine that you want in your pool. There are a number of influences can bring out rapid shifts in a pool's pH. These include:

  • Rain
  • Swimmer wastes
  • Refill water
  • pH of various pool chemicals

CAL HYPO - pH 11.7


Mustard Algae: Common algae in pools appears yellow-brown or "mustard" colored. It brushes off the walls of the pools easily, but quickly returns. It often rows in shady areas with poor circulation. It resists chlorine and shock treatment.

Solution: Use Yellow X along with chlorine shock. Follow label directions. Place all vacuum equipment (hose, head, pole, brushes, etc.) into pool during treatment. Maintain a higher than normal chlorine reading for 4 to 5 days after treatment.

Green Algae: Green algae is one of the most common problems for pools. It usually appears in corners or other areas where circulation is poor. Once established, green algae can grow explosively.

Solution: Use Algaecide 60, Algaecide 50, QLF Algaecide, or Copper Algaecide along with shock and Majestic Blue. Follow label directions. Yellow X along with chlorine shock could also be used in the place of algaecide. It is also recommended to use Hydrofloc, and to always vacuum to waste or drain (not backwash).

Black Algae is a very resistant form of algae that clings to the pool's walls, floor, and cracks. The longer black algae is present, the longer it will take to get rid of it. Black algae can actually pit the marcite finish in a gunite pool. Treat black algae as soon as it is detected. Black algae is usually found in gunite/concrete pools.

Solution: Brush algae spots vigorously with a stiff algae brush and pour Algaecide 60 along the sides where spots are visible. Run filter continuously for one hour, then add chlorine powder, pouring on the spots along the side of the pool. Majestic Blue can also be added to improve water clarity. Turn off filter and leave off for several days.

Preventing Algae

WEEKLYBrush walls and pool floor
WEEKLYVacuum pool
WEEKLYUse a maintenance dose of algaecide
WEEKLYUse a maintenance dose of Majestic Blue
DAILYMaintain a proper chlorine reading
WEEKLYKeep properly balanced--recommended readings: Free chlorine: 1.0-2.0, pH: 7.2-7.6, total alkalinity: 80-120 ppm, hardness: 200-300 ppm, stabilizer: 35-60 ppm

Suggested Water Problem Procedure

When water is encountered in the ground during excavation of the pool, the following procedure will enable you to divert this water temporarily and keep the area dry during construction. Once the installation is complete, ground water will not disturb the pool because the internal hydrostatic pressure of the pool water is greater than that of the water beneath the pool, unless there exists an "Artesian Well" effect. In these situations, pressure from the water from nearby hills and slopes can "float" a liner. A trench filed with gravel and drainage pipe must be dug to divert this water around the pool. It is also advisable to install a hard bottom instead of a sand bottom, thereby eliminating the possibility of a wash out of the pool base.

  1. Over dig hopper bottom 1 to 2 feet deeper than liner print and place #2 crushed stone (4 to 6 yards, depending on size of the pool and severity of water problem).
  2. If water is erupting from other areas such as the slopes or break over, over-dig or trench these areas and place stone so that the water will drain to the hopper bottom. (Note: Be sure to over-dig enough to allow for the addition of the rock and 2 inches of pool bottom material)
  3. Next get enough length of PVC or other pipe (minimum 1 1/2 inch diameter) so that you will be able to embed one end into the stone in the hopper, while embedding and running the rest of the pipe up the slope and under the panels to ground level. Note: Be sure the pipe end is located at the bottom of the stone bed at the deepest point. Install a 1/2 inch foot valve at the end of the pipe to be inserted into the stone. This will provide a screen and check valve.
  4. Connect the pipe to a low head electric pump and leave the discharge line slightly elevated so as not to lose prime. Turn it on and leave it running until the pool is finished and is filled with water. Cap off the line and leave it for future use in liner replacement.