POOL CHEMISTRY

1.      WHAT POOL CHEMICALS DO I NEED?

a.       Chlorine either in the form of liquid, dry, or stable dry.

b.      Acid, either in the form of liquid (muriatic acid), or dry (sodium bisulphate).

c.       Algaecide, either in the form of liquid or dry granular or tablet. (if chlorine and acid are used properly, this product may not be necessary).

d.      Soda ash, either in granular or block form (if too much acid is used).

2.      TYPES OF CHEMICALS

A.     CHLORINE

1.      Liquid Chlorine (SODIUM HYPOCHLORITE). This form of chlorine is made in a concentrated from especially for pool use. It contains between 10% and 16% available chlorine. Liquid chlorine may be poured directly into the pool but it should be distributed over as wide an area of the pool as is practical. Avoid contact of liquid chlorine with clothes and delicate tissue.

1.      Dry Chlorine (CALCIUM HYPOCHLORITE) This type of chlorine is available in either granular or tablet forms. It usually contains 70% available chlorine. The granular form dissolves readily while the tablets usually take several hours. Calcium hypochlorite contains an insoluble ingredient that leaves a residue in the pool. The granular and tablet form should be introduced in a floating chlorine dispenser.

B.     ACID

1.      Liquid Acid (MURIATIC). This product is quite strong and must be handled and used with great care. This material will burn skin, clothes and almost anything it comes in contact with. KEEP THIS PRODUCT AND ALL POOL CHEMICALS OUT OF THE REACH OF CHILDREN.

2.      Dry Acid (SODIUM DISULPHATE). This product is easier to store but it also must be used with care. When mixed with water this product is an effective pH reducer.

C.     ALGAECIDES. There are some chemicals that have been developed primarily to control and kill algae. Since there are many different such compounds, it is best when using them, to be guided by the manufacturer’s instructions. Generally chlorine must be used in conjunction with algaecides.

D.     CHLORINE STABILIZER (CONDITIONER). The use of this substance assists in the stabilization of chlorine to permit longer periods of protection. If stable chlorine is used as a regular source of chlorine the conditioner need be added only once with each filling of the pool. If other types of chlorine are used, the stabilizer should be replenished about every 3 to 4 weeks. See directions on stabilizer container regarding the amount to use.

1. HOW MUCH CHLORINE IS REQUIRED? It is advisable to follow the directions of the manufacturer for his particular products. As a rule this will provide dosages that will produce satisfactory results for normal treatment. During the initial start up, it is advisable to double the dosages shown for the first few days.

* Due to stabilization action, test pool for chlorine before adding. If chlorine is   present in water reduce dosage proportionately.

   For effective control of bacteria and algae maintain a chlorine residual of 0.3 to 0.6 ppm. If stabilized chlorine is used, a residual of at least 1.0 ppm should be maintained.

1.      HOW MUCH STABLE CHLORINE IS REQUIRED? – The stabilizing effect does not take place at one with regular use of chlorinated cyanuric acid, unless a conditioner is used with the initial treatment. Without use of conditioner the dosage of stable chlorine will have to be increased to double the normal treatment for the first 3 or 4 weeks. Afterwards, the average pool will require a dosage of between 1 and 2 oz. per 10,000 gallons of water.

2.      HOW IS THE POOL CONDITIONED TO ELIMINATE THE STABILIZING WAITING PERIOD? – By adding 1 pound of conditioner (cyanuric acid) to the pool for every 3000 gallons a residual stabilizing concentration of 40 ppm will be established. This will normally achieve chlorine stabilization.

3.      WHY DO I NEED TO USE ACID IN MY POOL? – The addition of some chlorine raises the pH since liquid (sodium hypochloride) tablet or granular (calcium hypochloride) are basically alkaline, continued use increases the pH above 7.6. to counteract this an acid must be used. Sodium bisulphate or muriatic acid will reduce the alkalinity.

4.      HOW MUCH ADIC DO I USE? – There are acid demand test kits available at your pool store that will tell you exactly how much acid is required at any one time. Be cautious when adding acid to prevent contact with tissue or clothing. Never put more than one pint of muriatic or 1 lb. of sodium bisulphate into a pool at one time. Wait four (4) hours and test pH before adding more acid.

1.      WHY DO I NEED TO USE SODA ASH IN MY POOL? – The pH at times may drop lower than 7.2 by adding too much acid or from the presence of some foreign material in the water. Use soda ash to raise pH to safe level.

2.      DO I ADD CHEMICALS TO MY FILTER? – NO! Pool chemicals should not be added directly to filter or surface skimmer. Diatomaceous earth is the only item that should be added to skimmer of filter.

3.      HOW DO I ADD CHEMICALS TO THE POOL? – A predetermined amount should be selected and filter should be running. Caution. Protect your eyes, skin and clothing at all times. Do not mix different chemicals. Do not add different chemicals to pool at the same point.

A.     Liquid Chlorine – pour slowly into the water by walking around the pool. Place container as close to water as possible to avoid splashing.

B.     Dry Chlorine – Granular or Tablet – can be placed in a floating chlorine dispenser. Do not pour any un-dissolved powder into pool because this may cloud water, shorten filter cycle, or settle to bottom and stain the poor liner.

C.     Dry Stable Chlorine – Granular, powder or tablet should be placed in a floating dispenser

D.     Muriatic Acid – Dilute acid 10 to 1 or 20 to 1 with water in a plastic bucket and slowly pour solution into water while walking around pool.

A.     Sodium Bisulphate – dissolve in a gallon of water (use plastic bucket) and slowly pour diluted liquid into water while walking around pool. Acid normally will react and be completely neutralized in 30 minutes with good pool circulation.

B.     Soda Ash – pre-dissolve soda ash in water and slowly add solution to pool water.

12.      WHEN IS THE BEST TIME FOR CHLORINATION? – In the evening after the sun has gone down and the day’s swimming is over. High temperatures and sunlight tend to dissipate chlorine rapidly.

13.      WHEN IS THE BEST TIME TO ADD ACID? – In the morning, however, one should test the water for chlorine residual and pH prior to the addition of any chemicals.

14.      WHEN SHOULD I TEST FOR CHLORINE RESIDUAL? – In the morning, before swimmers into the pool. If the bathing load has been heavy in the morning, an afternoon test is suggested to be sure the water is always properly chlorinated for healthful swimming.

15.      HOW DO I TEST FOR CHLORINE? – By using your pool test kit. This may either be in the form of single chlorine test set or a duplex test kit in which you can test for chlorine and pH. The chlorine test set, either OTO or DPD indicates the concentration of chlorine in the water by a simple color change of pool water sample which is compared to standard color codes. To be sure of the chlorine residual this test should be made daily.

16.      WHAT IS SUPERCLORINATION? – (SHOCK TREATMENT) – Continued low concentrations of chlorine tend to permit strains of organisms to develop which are more resistant to the normal concentration of chlorine. Because of this it is advisable to apply shock treatment, or superchlorination treatment, to control these organisms and also to burn out other accumulation of organic matter. This type of treatment calls for from five to ten times the normal dosage of chlorine once every two or three weeks.

17.      COMBINED CHLORINE – Common Problem – When chlorine becomes combined there are some indications which often appear:

1.      A Strong test of chlorine (this is a reading of chlorine in an unusable from).

2.      A strong odor of chlorine (not found when chlorine and pH are in balance).

3.      Swimmers complain of eye irritation (this is not a normal reaction of a bather to chlorine).

4.      Water tends to be cloudy or grayish.

To correct this condition (and almost all normal problems) one should:

1. ADJUST pH (so that chlorine is available to perform its three (3) basic functions: to kill bacteria – to kill algae – to destroy organic matter in the water).

2. SUPER-CHLORINATE OR SHOCK. With the adjusted pH, this super-chlorinization will drive off the unusable forms of chlorine which cannot be restored, and replace them with usable forms of chlorine (in a proper pH condition) which is now available to perform the three (3) basic functions which chlorine is intended to perform: to kill bacteria – to kill algae – to destroy organic matter.

Again, it is good practice to super-chlorinate once every two or three weeks.