Staining in pools and spas can be very challenging to prevent or remove because there is a lot of confusion as to what actually caused the stain. The first order of business is to determine what the staining is, which in most cases is either non-living organics or metals.
Problem: Stain Identification and Removal
Place a Vitamin C tablet on the stain and let it sit for at least 2 minutes. If the stain is unaffected by the Vitamin C, the stain is most likely non-living organic. Non-living organic stains are caused by leaves, worms, acorns and more. If the stain is lightened or removed by the Vitamin C tablet, it is most likely a metal stain.
Image of stain here
Solution to remove non-living organic stains:
Non-living organic stains are usually green and brown in color and often look like algae. To remove non-living organic stains, elevate the level of chlorine to hit breakpoint and scrub the area vigorously with a surface appropriate brush. After 24 hours, ensure chlorine levels have returned to normal range (below 5ppm) and broadcast Pool First Aid as around the perimeter of the pool and brush again. The concentrated enzyme and clarifier in the Pool First Aid will help break down the non-living organics and coagulate any small particulates. It is highly recommended to continue on a weekly regimen of Pool Perfect to help prevent the non-living organic stains from reoccurring.
Solution to remove metal stains:
Stains that are dark or reddish brown are typically metallic, and often come from iron and copper. Metals can come from numerous sources such as fill water-especially well water, or may have been introduced into the water as a result of corrosion caused by unbalanced water chemistry. Use either of the Stainfree (Stainfree is citric acid, Stainfree Extra Strength is ascorbic acid) products to remove metal surface staining or water discoloration (see water discoloration section for more information
). Follow up this application of a Stainfree product with an initial dose of METALfree per the Stain Removal Instructions