• TESTING ALKALINITY
• LOWERING ALKALINITY
• HOW TO ADD ALKALINITY DECREASER
• HOW TO ADD MURIATIC ACID
• FACTORS THAT LEAD TO HIGH ALKALINITY
• PROBLEMS RESULTING FROM HIGH ALKALINITY
• RAISING ALKALINTIY
• HOW TO ADD ALKALINTIY INCREASER
• HOUSEHOLD BAKING SODA
• FACTORS THAT LEAD TO LOW ALKALINITY
• PROBLEMS RESULTING FROM LOW ALKALINITY
• IDEAL READING FOR ALKALINTY

TESTING ALKALINITY: Do not confuse an alkaline-demand test with an Alkalinity test. An alkaline test is an optional test that is only performed after the pH test to determine how much alkaline material (pH Increaser or Soda Ash) is needed to raise the pH from below 7.19 to between 7.2 - 7.8. This alkaline test, then, is an extension of the pH test in order to elicit the most accurate and telling results for pH. An Alkalinity test is simply a test to measure the Total Alkalinity of the water. The Alkalinity of your pool is determined by the type of your pool, your chosen sanitizer/disinfectant/oxidizer, and your chosen shock.

There are two ways to test for Alkalinity: test strips or test kits.

The use of test strips is really self-explanatory. Read the instructions on the bottle for all of the "how to" instructions. Most test strips will test for pH and the chosen sanitizer/disinfectant/oxidizer, as well as the Alkalinity. Here are steps to using test strips:

• Take out one test strip and then recap the bottle.
• Dip the test strip into the water (usually about 18" below the surface of the water).
• Hold the test strip out of the water for the required amount of time.
• Compare the colors of the test strip to the colors of the chart on the bottle to determine if the Alkalinity reading is low, in range, or high.
• If applicable, adjust the pH.

The use of test kits is also popular. Read the instructions on the test kit for all of the "how to" instructions. Many test kits will test for only pH and the chosen sanitizer/disinfectant/oxidizer, while other test kits add the capability to include Alkalinity, and perhaps certain other chemicals. It is a good idea to purchase a test kit that will also test for Alkalinity. Here is a discussion:

The reagent to test Alkalinity is simply called an Alkalinity reagent. A test for alkalinity is a titration test, which means it requires an indicator reagent and a follow up reagent. Once the test block is filled with sample water from the pool, an indicator reagent is added to the sample, which changes the color of the water. Then, a follow up Alkalinity reagent is added, drop-by-drop. The number of drops to change the color of the water (as specified in the instructions of your test kit) will determine the Alkalinity. Simply take the number of required drops and multiply it by 10 to determine your Alkalinity. Here's an example:

• You add your indicator reagent to establish a color. You then add your follow up Alkalinity reagent, drop-by-drop, always counting as each drop is added. It takes 10 drops to fully change the color. Therefore, your alkalinity is 100 ppm.

  (10 drops x 10 = 100 ppm = Alkalinity reading).

LOWERING ALKALINITY: If an Alkalinity test shows the Alkalinity level to be too high, then the Alkalinity must be lowered. There are two chemicals to lower Alkalinity-the same chemicals that lower pH (Sodium Bisulfate or muriatic acid) will also lower Alkalinity. If you recall from our discussion on lowering pH, the manufacturers recommend varying amounts to add per 10,000 gallons of water, as well as recommend varying application procedures-some say to dilute the product in a bucket of water and then pour it into the pool, while others say to broadcast it into the pool directly from the package. Therefore, poolmanual.com will not attempt to allocate a universal application. You must simply test the water, determine how high the Alkalinity is, and then read the instructions on the label to determine the proper amount of pH Decreaser (Sodium Bisulfate) or muriatic acid to add-again, remember that the same chemicals that lower pH will also lower Alkalinity. If the Alkalinity of your pool is allowed to get too high, then the Alkalinity must be lowered in increments, as all manufactures will indicate a maximum amount of product that can be added per 10,000 gallons of water at one time. Although poolmanual.com will not allocate a universal application, we will include a guideline. Please remember, this is only a guideline, and we still recommend that you read the instructions before making any additions. The following sentences provide an easy guideline:

• Typically, by adding 24 oz (1 ½ LBS) of pH Decreaser (Sodium Bisulfate) per 10,000 gallons of water, or by adding 20 fluid oz of muriatic acid per 10,000 gallons of water, the Alkalinity will be decreased by 10 ppm. If the Alkalinity is extremely high, then the Alkalinity must be lowered in increments, but again, never adding more than 24 oz (1 ½ LBS) of pH Decreaser per 10,000 gallons of water or 20 fluid oz of muriatic acid per 10,000 gallons of water AT ONE TIME.

If your high Alkalinity reading requires more than the maximum amount to be added at any one time, then you will have to add the chemical in increments, allowing 6 hours between applications. Having such a high Alkalinity reading will cause frustration. The main reason is that most test strips and test kits only read Alkalinity up to 180 ppm, but Alkalinity can be much higher. You may add the specified maximum amount per 10,000 gallons of water every 6 hours, but come back to test the Alkalinity and still find it too high. You may have lowered the Alkalinity from 320 ppm to 190 ppm, but since test strips and test kits will not read this high (again, they only read Alkalinity up to 180 ppm), it may seem as though nothing has been accomplished in lowering Alkalinity, when in actuality, significant improvements have been made. If this happens to you, go visit your local pool professionals and have them test your chemicals on the computer so that you know the absolute Alkalinity level of your water. Listen to their advice, and within the week, go back for a follow-up analysis on the computer. Once Alkalinity is in range, monitor the Alkalinity closely and keep it within the desired range so that you don't have to make such drastic, incremental, and time-consuming adjustments. Also, having such a high Alkalinity can cause structural and equipment damage.

HOW TO ADD ALKALINITY DECREASER (SODIUM BISULFATE): "Alkalinity Decreaser" is the same chemical as pH Decreaser-there is no chemical packaged and sold as an Alkalinity Decreaser. Read the instructions on the label. Once you determine how much to add and how it should be applied (either diluted or broadcast), pour a portion of the pH Decreaser in front or each return jet-the return jets will disperse the pH Decreaser throughout the pool water. If the manufacturer of the pH Decreaser that you purchase to lower your Alkalinity does not require it to be diluted, then secure yourself on the pool deck, bend down very close to the surface of the water, and still pour the pH Decreaser in front of each return jet. Since the granules are so powder-like, the wind can blow them out of the pool, or worse, in your face or eyes. Therefore, secure yourself close to the surface of the water and be careful not to fall into the pool.

Often, when lowering Alkalinity, Sodium Bisulfate is not required to be diluted. When diluted, pH Decreaser may reduce the pH without administering any major effects on the Alkalinity. Therefore, read the instructions. Regardless of how it is applied (diluted or broadcast), never pour pH Decreaser, or ANY chemical, into the skimmer(s).

NOTE: For an aboveground pool, reach over the wall, get close to the surface of the water, and add the pH Decreaser.

NOTE: pH Decreaser (Sodium Bisulfate), as well as muriatic acid, lower BOTH pH AND Alkalinity.

HOW TO ADD MURIATIC ACID: Muriatic acid, which lowers pH, will also lower Alkalinity. Read the instructions on the label. Once you determine how much to add and how it should be applied (either diluted or broadcast), pour a portion of the muriatic acid in front of the deep end return jet-this return jet will help disperse the muriatic acid throughout the pool water. Regardless of how it is applied, be sure to secure yourself on the pool deck, bend down close to the surface of the water, and pour the muriatic acid in front of the deep end return jet. Be careful not to fall into the pool.

Often, when lowering Alkalinity, muriatic acid is not required to be diluted. When diluted, muriatic acid may reduce the pH without administering any major effects on the Alkalinity. Therefore, read the instructions. Regardless of how it is applied, never pour muriatic acid, or ANY chemical, into the skimmer(s).

If muriatic acid gets on your skin, it will burn. If this happens to you, immediately flush your skin with water. If muriatic acid gets into your eyes, it will severely burn. Do not rub your eyes after handling muriatic acid. If it does get in your eyes, though, flush them with water and seek emergency assistance immediately. This is a good time to mention that it is a good idea to wash your hands after dealing with ANY chemicals.

NOTE: For an aboveground pool, reach over the wall, get close to the surface of the water, and add the Muriatic Acid.

FACTORS THAT LEAD TO HIGH ALKALINITY: These factors can raise the Alkalinity of your pool water:

• Tap water in certain regions simply has a high Alkalinity level.
• Overestimating the amount of Alkalinity Increaser that is needed.

If these, or any other, reasons cause your Alkalinity to be high, you must lower it immediately, using either Sodium Bisulfate (which is typically packaged and sold as "pH Decreaser," "pH Down," or "pH Minus") or muriatic acid.

PROBLEMS RESULTING FROM HIGH ALKALINITY: If the Alkalinity of your pool is high, these problems will occur:

• Cloudy water.
• Scale formation on the pool walls, floor, plumbing and equipment.
• Short filler runs and overall poor filtration - primarily due to scale that is deposited inside the plumbing, which restricts water circulation.
• Minimizes the effectiveness of chlorine (or its alternative).
• pH will be difficult to adjust.
• Eye and skin irritation.

If these, or any other, problems occur due to high Alkalinity, you must lower the Alkalinity immediately, using either Sodium Bisulfate (which is typically packaged and sold as "pH Decreaser," "pH Down," or "pH Minus") or muriatic acid.

RAISING ALKALINITY: If an Alkalinity test shows an Alkalinity level to be too low, then the Alkalinity must be raised. There are two chemicals to raise Alkalinity, but poolmanual.com will only endorse and recognize one of these chemicals. This chemical is a granular product, which is typically packaged and sold as "Alkalinity Increaser," "Alkalinity Up," or "Alkalinity Plus" (the product is also often referred to by its scientific name, which is Sodium Bicarbonate). Some pool professionals do recommend household baking soda to raise Alkalinity. This is technically justifiable, because household baking soda is a sodium bicarbonate. But, its manufacturers offer no directions for pool use. Therefore, if you use it, then you are on your own. If the manufacturers of household baking soda cannot provide directions, then how can we?

Before adding any Alkalinity Increaser, read the instructions on the label. Manufacturers will recommend varying amounts to be added per 10,000 gallons of water, as well as recommend varying application procedures-some say to dilute the product in a bucket of water and then pour it into the pool, while others say to broadcast it into the pool directly from the package. Therefore, poolmanual.com will not attempt to allocate a universal application. You must simply test the water, determine how low the Alkalinity is, and then read the instructions on the label to determine the proper amount of Alkalinity Increaser to add. If the Alkalinity of your pool is allowed to get too low, then you must lower the Alkalinity in increments, as all manufacturers will indicate a maximum amount of product that can be added per 10,000 gallons of water at one time. Although poolmanual.com will not allocate a universal application, we will include a guideline. Please remember, this is only a guideline, and we still recommend that you read the instructions before making any additions. The following chart will provide a guideline:

	10ppm	25ppm	50ppm	75ppm	100ppm	150ppm
5,000	2LBS	3LBS	4LBS	5LBS	6LBS	8LBS
10,000	4LBS	5LBS	6LBS	7LBS	8LBS	11LBS
15,000	6LBS	8LBS	10LBS	11LBS	12LBS	17LBS
20,000	8LBS	10LBS	14LBS	15LBS	17LBS	23LBS
25,000	10LBS	14LBS	18LBS	19LBS	22LBS	29LBS
30,000	12LBS	16LBS	22LBS	23LBS	27LBS	36LBS
35,000	14LBS	18LBS	26LBS	28LBS	32LBS	43LBS
40,000	16LBS	22LBS	30LBS	32LBS	37LBS	50LBS
50,000	21LBS	27LBS	35LBS	38LBS	44LBS	59LBS

How does the chart work:

• The TOP HORIZONTAL ROW will show the ppm values that the Alkalinity must be raised in order to get into the ideal range.
• The FIRST VERTICAL COLUMN will show the approximate gallons of water for your pool.
• The numbers in the boxes will show how many pounds of Alkalinity Increaser (Sodium Bicarbonate) are needed in order to get the Alkalinity in the ideal range.

You will need to test and determine your Alkalinity level and then determine how much it needs to be raised (which again is noted on the TOP Horizontal Row). Just follow the TOP Horizontal Row down and the FIRST Vertical Column across until they meet, in order to determine how many pounds of Alkalinity Increaser (Sodium Bicarbonate) to add in order to get your Alkalinity in the ideal range. Let's look at an example:

• A pool owner has a vinyl-liner pool (ideal Alkalinity range = 100-140 ppm), which is 30,000 gallons. This pool owner uses chlorine tablets (ideal Alkalinity range = 100-120 ppm), and uses Calcium Hypochlorite to shock the pool (ideal Alkalinity range = 80-100 ppm). As you see from this example, 100 ppm is either a low, mid-range, or high accepted Alkalinity reading. Therefore, in this example, the pool owner should attempt to achieve and maintain an Alkalinity reading of 100 ppm. The Alkalinity level of this pool is currently only 25 ppm; if this pool owner was a poolmanual.com subscriber, this would not have happened. The Alkalinity level must be raised. Therefore, to reach the ideal range of 100 ppm, the pool owner from this example must raise the Alkalinity by 75 ppm.

  100 ppm (desired) -25 ppm (current) = 75 ppm.

• So, by following "75" on the TOP Horizontal Row and tracing it down, AND by following "30,000 gallons" on the FIRST Vertical Column and tracing it across, the corresponding number of pounds of Alkalinity Increaser (Sodium Bicarbonate) to raise the Alkalinity 75 ppm (FROM 25 ppm TO 100 ppm) is 23 LBS.
• Be careful. Remember, you can only add a specified maximum amount per 10,000 gallons of water at one time. Typically, 4LBS per 10,000 gallons of water is a widely agreed upon maximum that can be added AT ONE TIME. You can only find this specified maximum amount by reading the instructions on the label of the chemical (Alkalinity Increaser) that you have purchased. If the amount that you need to add is MORE than the maximum amount that can be added at one time, then you will need to raise the Alkalinity in increments, allowing 6 hours between additions.

Typically, a widely agreed upon maximum amount of Alkalinity Increaser to be added at one time is 4LBS PER 10,000 GALLONS OF WATER; if you have a 20,000 gallon pool, you can add 8LBS of Alkalinity Increaser. But again, read the instructions on the label to make sure. Although having a very low Alkalinity reading will cause frustration, at least most test strips and test kits do read Alkalinity down to 0 ppm, so you will know the absolute value of your Alkalinity level. But, if you are adding the maximum amount of Alkalinity Increaser every 6 hours and still testing it as constantly low, then go visit your local pool professionals and have them test your chemicals on the computer, so that you really will know the absolute Alkalinity level of your water. Listen to their advice, and within the week, go back for a follow-up analysis on the computer. Once the Alkalinity is in range, monitor the Alkalinity closely and keep it in range so that you don't have to make such drastic, incremental, and time-consuming adjustments. Also, having such a low Alkalinity level can cause structural and equipment damage.

HOW TO ADD ALKALINITY INCREASER (SODIUM BICARBONATE): Read the instructions on the label. Once you determine how much to add and how it should be applied (either diluted or broadcast), pour a portion of the Alkalinity Increaser in front of the deep end return jet-this return jet will disperse the Alkalinity Increaser throughout the pool water. If the manufacturer of the Alkalinity Increaser that you purchase does not require it to be diluted, then secure yourself on the pool deck, bend down very close to the surface of the water, and still pour the Alkalinity Increaser in front of the deep end return jet. Since the granules are so powder-like, the wind can blow them out of the pool, or worse, in your face and eyes. Therefore, secure yourself on the pool deck and be careful not to fall into the pool. Regardless of how it is applied (diluted or broadcast), never pour Alkalinity Increaser, or ANY chemical, into the skimmer(s).

NOTE: For an aboveground pool, reach over the wall, get close to the surface of the water, and add the Alkalinity Increaser.

HOUSEHOLD BAKING SODA: if you are using baking soda to raise your Alkalinity, then you are on your own. Baking soda is a household product that is not marketed or intentionally sold for pool applications. Therefore, manufacturers offer no directions for pool use. If you use baking soda, please be careful when adding it to your pool. Household baking soda is Sodium Bicarbonate, so it is not at all dangerous for pool use. But since manufacturers do market and sell baking soda for pool use, and since they offer no application procedures, poolmanual.com will not recommend household baking soda as a recommended alternative to Alkalinity Increaser (Sodium Bicarbonate).

FACTORS THAT LEAD TO LOW ALKALINITY: These factors can lower the Alkalinity of your pool water:

• Tap water in certain regions has a low Alkalinity level.
• Overestimating the amount of pH Decreaser or the amount of muriatic acid that is needed-again, pH Decreaser, as well as muriatic acid, lower both pH AND Alkalinity.
• High bather loads.
• Swimmer wastes, such as perspiration, urine, saliva, and other body oils.
• Dirt, debris or leaves that blow into the swimming pool.
• The acidic level of rain will often lower pH, and perhaps the Alkalinity as well.

If these, or any other, reasons cause your Alkalinity to be low, you must raise it immediately, using Sodium Bicarbonate (which is typically packaged and sold as "Alkalinity Increaser," "Alkalinity Up," or "Alkalinity Plus").

PROBLEMS RESULTING FROM LOW ALKALINITY: If the Alkalinity of your pool is too low, these problems will occur:

• Dissolved metallic parts of your pool (walls, floor, hand rails, ladders, light fixtures, and equipment). This could even lead to discolored water or stains on the pool walls and floor.
• Stained and etched concrete in concrete pools.
• Stained and etched plaster in gunite or shotcrete pools.
• Stained liner in vinyl-liner pools.
• Blistering or delamination of fiberglass in fiberglass pools.
• "pH Bounce." Alkalinity acts as a buffer for pH. If the Alkalinity is low, the pH will fluctuate dramatically. Yesterday, it may have been 7.0, and today it may be 7.8, and tomorrow it may be 6.8-it can change from one extreme to the next, literally overnight.
• Minimizes the effectiveness of chlorine (or its alternative).
• Eye and skin irritation.

If these, or any other, problems result due to low Alkalinity, you must raise the Alkalinity immediately, using Sodium Bicarbonate (which is typically packaged and sold as "Alkalinity Increaser," "Alkalinity Up," or "Alkalinity Plus").

IDEAL READING FOR ALKALINITY: An ideal reading for Alkalinity will vary due to three variables: (1) type of pool, (2) type of sanitizer/disinfectant/oxidizer, and (3) type of shock. Here are the ideal readings for each variable:

• Type of pool:

  Concrete Gunite Shotcrete Vinyl-liner Fiberglass

  100-140 ppm 80-120 ppm 80-120 ppm 100-140 ppm 100-140 ppm

• Sanitizer/Disinfectant/Oxidizer:

  Liquid Chlorine Granular Chlorine (Dichlor) Chlorine Tablets (Trichlor) Bromine Alternatives to Chlorine-consult the pool professionals that sold you the alternative.

  80-100 ppm 100-120 ppm 100-120 ppm 100-120 ppm

• Shock:

  Calcium Hypochlorite Lithium Hypochlorite Potassium Peroxymonosulfate

  80-100 ppm 80-100 ppm 80-120 ppm

NOTE: "100" is either a low, mid-range, or high value for every variable. Therefore, attempt to achieve and maintain your Alkalinity level at or near 100 ppm.