Sodium Bisulfate is a dry acid, which is readily soluble in water. Applications include reducing pH in pool, spas, water treatment systems, as an acid using in metal finishing and as an ingredient in acidic cleaning formulations. It uses to lower pH and Alkalinity. Sodium Bisulfate is also known as "pH Decreaser," pH Down," or "pH Minus." 

Sodium Bisulfate is granular, and is commonly referred to as "dry acid" (as opposed to the liquid Muriatic Acid, which is an alternative to lowering pH and Alkalinity). The pH level of your pool affects every other chemical balance in pool water. pH is a measure of the level of hydrogen ions or acidity of the pool water. Measured on a logarithmic scale, a pH of 0 indicates extremely acidic conditions, and a pH of 14 indicates extremely basic conditions. A pH of 7 is neutral.

The most desired pH of pool water is between 7.2 to 7.6, slightly basic. This is the most comfortable range for your eyes and skin, and provides the optimum chlorine levels to prevent bacteria, algae and fungus growth, without developing scale, the white crusty substance often seen on pool tiles, or becoming too corrosive. Dry acid is often used to adjust pool water back towards this optimum range when it has become too basic.

Test pH weekly. The recommended range is between 7.2 and 7.6. If the pH is higher than 7.6, correct it by adding the Dry Acid.


  • To lower pH: Measure the pH of pool water with a test kit. Broadcast over the deepest part of the pool using the following dosages based on pH. For shallow pools, dissolve in a pail of water before adding to pool.
  • Recommended Dosage for pH 7.8-8.0: 4 oz per 10,000 gallons of water
  • Recommended Dosage for pH 8.0-8.4: 8 oz per 10,000 gallons of water
  • Recommended Dosage for pH above 8.4: 12 oz per 10,000 gallons of water
  • To lower alkalinity: Keep the total alkalinity between 80-120 parts per million (ppm). Test for total alkalinity with a test kit each month. If alkalinity is light, follow usage below.
  • Recommended Usage for light alkalinity: add 2 lb of pH Minus for each 10,000 gallons of pool water to lower alkalinity to 10 ppm. Keep the circulation pump running. Add this product in one spot at the deep end of the pool. Do not apply near walls or metal fixtures. Repeat daily until desired alkalinity is reached.


This depends on just how high the pH is and the size of the pool. The amount calculations are not exact. It is always best to add less than the full amount, wait a little while to allow the addition to mix thoroughly, and then retest to see where you are. Read the instructions on the label to determine the amount to add, how it must be added (either diluted in water or broadcast straight from the container), a maximum amount (per 10,000 gallons of water) that can be added at one time, and other precautions. If you have a smaller pool, or an above-ground pool, you would start with one cup of acid, and then re-test and add more if needed. 

pH is a measure of how acidic or alkaline the water is. The pH scale ranges from 0 to 14, with 7 being neutral. Values below 7 are acidic and values above 7 are alkaline. With pool water we are seeking a pH balance suitable to the pool users, the pool and the sanitiser used. The operating range as 7.0 to 7.8, ( 7.0 to 7.2 for fiberglass pools and 7.4 to 7.8 for concrete pools). Topping up your pool, heavy rain, heavy bathing loads and chemical additions can all change the pH level of your pool water. pH must be kept within the operating range because if it is too high or too low it may:

  • Create swimmer discomfort (itchy skin, red eyes etc.)
  • Interfere with the sterilising action of your pool sanitiser.
  • Cause damage to the pool surface.
  • Damage the pool equipment

It is one of the most important aspects of your pool maintenance program.



Amount of Sodium Bisulfate or Dry Acid to lower swimming pool pH:

Liters in Pool
7.6 - 7.8
45 g  
225 g  
455 g  
600 g  
900 g  
1.2 kg  
2.4 kg  
4.8 kg  
7.8 - 8.0
55 g  
300 g  
600 g  
900 g  
1.2 kg  
1.5 kg  
3 kg  
6 kg  
8.0 - 8.4
95 g  
455 g  
900 g  
1.5 kg  
1.8 kg  
2.4 kg  
4.8 kg  
9.6 kg  
Over 8.4
115 g  
600 g  
1.2 kg  
1.8 kg  
2.4 kg  
3 kg  
6 kg  
12 kg  


Industries Using Sodium Bisulfate:

  • Chemical Distributors
  • Metal Treating
  • Swimming Pool
  • Chemical Manufacturing
  • Cleaning Compounds
  • Agriculture
  • Water Treatment

(A) Swimming Pool Chemical
Sodium Bisulfate is used for pH reduction in swimming pools and spas. Dry acid is the safest product to use for home and institutional pools and spas. Usually, 1 - 2 lbs. applied in a 10,000 gallon pool will adequately reduce the pH. If after one or two hours the pH is above 7.8, repeat the treatment until the pH is between 7.2 and 7.6.

(B) Metal Finishing
It is the major component in dry acid bath formulations for metal cleaning. The general formula for most acidic baths include: salts of fluorides (5-10%), Sodium Bisulfate (90-95%) plus a surfactant. The concentration is generally 4 oz. to 3 lbs. per gallon of water. At temperatures up to 170°F., this bath will clean steel, copper, brass, zinc, aluminum, nickel, magnesium, titanium and stainless steel. Typical uses are for pickling, scale removal, rust removal and etching.

(C) Adjuvant
Protects agricultural spray chemicals against product loss due to alkaline hydrolysis in spray solutions. The effectiveness of a number of agricultural pesticides is greatly diminished when added to water with high pH. Sodium Bisulfate works particularly well with glyphosate herbicides to enhance their effectiveness. Acidification with Sodium Bisulfate is recommended as an alternative to ammonium sulfate for use with many herbicides.

(C) Water Treatment
Sodium Bisulfate is used as a de-scaler in boilers, cooling towers, and water lines. It cleans and adjusts pH. If there is a need for effluent treatment of an alkaline substance, Sodium Bisulfate is recommended.

(D) Concrete Wash Out
Reduces alkalinity in “wash out” ponds formed by concrete truck clean out. Area concrete companies are potential distributor customers. Jones-Hamilton Co. technical service representatives can recommend pH adjustments.

(E) Leather Tanning
Sodium Bisulfate acts as the acidifier in leather compounds when used in combination with quebacho tannin. SBS is combined with fillers and other chemicals to acidify hides used for shoe sole leather.

(F) Chemical Grout
Sodium Bisulfate acidifies a grout formulation to form a temporary seal while constructing underground tunnels. Sodium Bisulfate is combined with aluminum sulfate, magnesium sulfate, and other fillers as a dry compound. This compound is then put in a water solution and combined with liquid sodium silicate for spraying on tunnel walls. The more SBS added, the faster the gel time of the grout formulation.

(G) Resist Treatment Powder
Sodium Bisulfate can be used as a component in compounds to treat aqueous and semi-aqueous photoresistant strippers and developers. The products neutralize the alkalinity of the stripper, coagulates the stripped resist, hardens the particles, and buffers the treated solution to a dischargeable pH.

(H) Cleaning Compounds
Sodium Bisulfate is the acidifier and cleaning ingredient in many compounds. Because of its consistent particle size, it is compatible with most formulae. It has been used in formulae for cleaning cement, railroad cars, brass, lavatories, showers, and metals. Contract packers producing their own brand name products and those repackaging for major companies are candidates for Sodium Bisulfate. It is the major component in most dry bowl cleaner formulations. A typical U.S. formulation consists of 64-70% Sodium Bisulfate by weight with salt, soda ash, surfactant and a dye. These cleaners are very popular for hard water areas that generate iron deposits.

(I) Remediation Acidifier
Sodium Bisulfate neutralizes alkaline soils for construction projects. It has been used as a direct additive to soil to adjust pH to a neutral or acceptable level before building permits are approved. In this use Sodium Bisulfate is generally tilled into the soil at the rate of 16,000 to 24,000 lbs. per acre depending on soil type. Tilling depth is 12 inches. This application reduces the pH by a factor of 2 (for example: from a pH of 8.5 to 6.5). It is recommended to spread Sodium Bisulfate dry, disc it in and irrigate.

(J) Boiler Blowdown
Sodium Bisulfate neutralizes boiler blowdown water before discharge into city sewers. Concentrated boiler water contains scale, mineral deposits, and traces of alkaline chemicals with an average pH of 11. Mix a 5010% Sodium Bisulfate solution in water and meter it to the treating system to reduce water pH to a range of 6-9 for discharge.

(K) Sulfamic Acid Replacement
Sodium Bisulfate is a popular substitute for sulfamic acid in many situations, because it costs less and is produced in the United States. Some uses include: descaling solutions, water treatment, compounding and most low pH requirements.

Pool Chemicals Delivery is not available for East Malaysia (Sabah/Sarawak) addresses.

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Pool pH Decreaser - Dry Acid pH Minus (22.68 kg/bag Sodium Bisulfate)

  • Product Code: AC0011
  • Availability: 3
  • RM500.00
  • RM285.00

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Tags: Dry Acid, Swimming Pool Chemicals, pH

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