STAIN REMOVAL - CALCIUM



The calcium stains will create a rough surface on swimming pool surfaces and equipment. The colour is usually yellow but can also absorb other colours from the swimming pool environment. (Grey – dirt, green – algae or copper, blue- copper, black – copper or iron, purple – manganese). Though the colours may be different the treatment is the same.

Calcium stains or deposits are a result of Calcium Carbonate coming out of solution. This reaction can be caused by the following :

  • High Calcium Hardness in the swimming pool
  • High Calcium Hardness in the source water
  • Poor water balance (high pH, CH and or TDS)
  • Poor water balance (low pH, CH)
  • Long term addition of a calcium based shock treatment
     

Calcium stains can be easily removed from pool surfaces and equipment. The ease of removal is related to how long the stains have been on the surface and how porous the surface is. The newer the stain and the smoother the surface the easier it will be to remove it.


  1. Add fresh water to the swimming pool. Bring water above normal levels.
  2. Adjust water balance and pH to 7.0.
  3. Add 200 ml of SHIELD per 10,000 litres of pool water.
  4. Brush stains daily during treatment.
  5. Monitor and maintain pH at 7.0.
  6. Backwash sand filter daily to remove suspended calcium.
  7. Repeat SHIELD treatment and continue brushing for stains not removed in one week.
  8. Return pH to the proper range 7.4 to 7.6.
  9. For Stain prevention add 25 mls. of SHIELD per 10,000 litres of water per week. If source water contains more than 350 ppm of Calcium Hardness consider diluting pool water with another source with a lower Calcium Hardness.

NOTE: DO NOT SUPERCHLORINATE OR SHOCK POOL PRIOR TO OR DURING STAIN REMOVAL TREATMENT!

NOTE: CALCIUM CARBONATE STAINS AGED INTO CONCRETE POOL SURFACES MAY REQUIRE LIGHT ACID WASHING.


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