Discoloration of spa or pool surfaces most often caused by metal corrosion of circulation system due to low pH Sequestering or chelating agent will remove stains, for tough stains acid wash may be necessary
A discoloration or a colored deposit on the walls or bottom of a swimming pool or spa Most often, stains are metals, such as iron, copper & manganese They may appear as green, gray, brown or black They may even discolor the water Sometimes a sequestering agent or chelating agent will remove them If not, us- ually an acid wash is necessary to remove them from the walls & bottom The metals get in the water because the pH was too low or someone has added a low-pH chemical directly into the circulation system The low-pH chem- ical dissolves a small amount of metal from the equipment The metals begin to come out of solutions & deposit or stain the walls & bottom Stains are sometimes confused with scale
To color, as wood, glass, paper, cloth, or the like, by processess affecting, chemically or otherwise, the material itself; to tinge with a color or colors combining with, or penetrating, the substance; to dye; as, to stain wood with acids, colored washes, paint rubbed in, etc
If a liquid stains something, the thing becomes coloured or marked by the liquid. Some foods can stain the teeth, as of course can smoking. + stained stained His clothing was stained with mud. + -stained -stained ink-stained fingers
a soiled or discolored appearance; "the wine left a dark stain" (microscopy) a dye or other coloring material that is used in microscopy to make structures visible color for microscopic study; "The laboratory worker dyed the specimen" color with a liquid dye or tint; "Stain this table a beautiful walnut color"; "people knew how to stain glass a beautiful blue in the middle ages" produce or leave stains; "Red wine stains the table cloth
(microscopy) a dye or other coloring material that is used in microscopy to make structures visible color for microscopic study; "The laboratory worker dyed the specimen"