Copper Sulfate Staining: Blue/Purple Splatter pattern, blotches.
Cause:
Liquid Algicides containing copper sulfate, Low PH, Over Acid, Rusted out heater and old copper pipes.
Note: Copper may be "in suspension" in the water for years, a sudden drop in PH(from acid) or a sudden rise
in PH (chlorine shock) can cause the copper to fall out. Staining the plaster blue
This pool plaster is less than 2 years old.
Calcium Staining (scale):
Off white, yellow stains, can encase total plaster area or splatter pattern on side walls and pool bottom also can form
as lines on walls and floor.
Cause: Cacium based Granular Chlorine,usage of packaged"shock"containing
calcium hypo-clorite, sudden drop in Ph (from acid), water in pool "dead" from high total dissolved solids,
not draining pool yearly.
Plaster Whitening Process: A solution is poured directly on the plaster
surface. Copper, magnesium and iron stains are sequestered from the plaster matrix as well as calcium.The result is the plaster
is restored to its original whiteness. The pool surface is then sanded with 25-36 grit ,leaving a smooth plaster finish.