Polyphosphate scale and corrosion  inhibitor media sold per Kg.

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 Description : Polyphosphate Scale Inhibitor

Polyphosphates are water purification chemicals that are employed to correct problems caused by inorganic groundwater contaminants (iron, manganese, calcium, etc.) and also to preserve water quality in distribution systems.

In the treatment of potable (drinking) water polyphosphates are used to:

  • Prevent “red” (from iron) and “black” (from manganese) water
  • Reduce soluble lead and copper in potable water
  • Clean or dissolve precipitated mineral scale already existent in water distribution lines
  • Prevent and/or retard scale formation (from minerals depositing) and corrosion (from low pH and/or dissimilar metals) in the water distribution system

Scaling is caused by the hardness salts present in water,  particularly the  compounds of calcium and magnesium.     The level of water hardness is categorised as follows:

Classification mg/L or PPM (parts-per-million) Grains per Gallon or GPG
  Soft 0 – 17 0 – 1
  Slightly Hard 17 – 60 1 – 3.5
  Moderately Hard 61 – 120 3.5 – 7.0
  Hard 121 – 180 7.0 – 10.5
  Very Hard 180 + 10.5 +


Below is a general guide to the water hardness in Australian capital cities –


Total Hardness as Calcium Carbonate mg/L

Melbourne 10 – 26
Hobart 5.8 – 34.4
Darwin 31
Canberra 40
Sydney 39.4 – 60.1
Perth 29 – 226
Brisbane 100
Adeliade 134 – 148


 Hard Water contains dissolved minerals in the form of Calcium (Ca), Magnesium (Mg), and Iron (Fe).  Hard water has a tendency  to form scale deposits  in pipes, hot water systems and on plumbing fixtures. It also reduces the ability of soap to dissolve in water and will form soap scum.Hard water is ideally treated by ion exchange water softeners.     There are other controversial methods used to treat water including magnetic and electromagnetic methods.  The efficacy of these treatments is based predominantly on testimonial evidence, and not widely accepted by the scientific community. More about  magnetic and electromagnetic water treatment.  

 Iron levels above 3 ppm are ideally removed with iron removal filters.


Polyphosphate scale and corrosion  inhibitor media sold per Kg.

100% polyphosphate granules are ideal for reducing and inhibit scale build up caused by  the permanent hardness salts of Calcium and Magnesium present in hard water.  

Polyphosphates do not remove iron or hardness salts from water. Generally, polyphosphate feeders are effective in low volume, cold water applications. The polyphosphate dissolves into the water and coats the iron, calcium and magnesium in it, making it impossible for these agents to precipitate out of the water and create the problems associated with hard water.

However, polyphosphate treatment may not prevent iron  or hardness salts from precipitating when water is boiled for a time, as in cooking or in the brewing of tea or coffee, as boiling can cause reversion to the orthophosphate which has no equivalent sequestering action.

Polyphosphates may inhibit corrosion mechanisms of aggressive or corrosive water supply.


Dosage Recommendations for polyphosphate:

  Typically, in order to sequester iron, manganese and calcium it requires a 1:1 mole ratio with polyphosphate.  This is generally achievable when dealing with iron and manganese that are usually in levels that are less than 5 mg/L.  However, polyphosphates act as crystal modifiers that need only a fraction of that ratio to effectively modify the crystalline structure of calcium/magnesium.    In theory, a hexametaphosphate dosage of 500 mg/L is required to actually sequester 200 mg/L of calcium (as calcium carbonate).  However, a dosage of only 2 -4 mg/L of hexametaphosphate is all that is required to modify the crystal growth of calcium carbonate.  By modifying the crystalline structure, these compounds will not precipitate into scale and actually stay in solution through repelling and suspension.  This crystal growth modification function prevents the formation of mineral scale within water distribution systems.  Polyphosphates will also dissolve already deposited mineral scale deposits within the system thereby increasing the carrying capacity of the water system.  Polyphosphates are cathodic inhibitors that interfere with the cathodic site of the electrochemical corrosion cell formation.


The polyphosphate is food grade and safe for drinking water applications.

CAS NO.: 94551-68-5
EINECS NO.: 233-343-1
Type: Chemical Auxiliary Agent
MF: (NaPO3)6
Polyphosphate can be combined with carbon if required.


We sell a range of empty filter cartridges that the polyphosphate can be used in.




Additional information

Weight 1 kg
Dimensions 10 × 10 × 5 cm


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