o Black – caused by OXIDISED COPPER
o Turquoise-Blue – caused by COPPER
o Rust-Brown – caused by IRON
o Coffee brown or Violet Purple – caused by MANGANESE
o Incorrect water balance
o Metal equipment e.g. Cast iron pumps and motors, metal piping.
o Use of products containing metal.
o Use of borehole water.
o 250 ml per 10,000 l of pool water when chlorine levels are at 1 ppm.
o Do not shock dose with chlorine for 7 days.
o Brush stains daily for 7 days.
o 25 ml per 10,000 l of pool water weekly.
o Brush pool surface frequently.
3. Use BioGuard Sparkle Up to trap and filter out metals.
4. Correct water balance.
Also refer to scaling