Stain Removers or Sequestring agents are used to control or remove metals and minerals from your pool. They coagulate the particles so the filter can remove them.  While most stain removers have phosphates in them (remember phosphates are the nutrients for algae) we want to limit the use of these types.  Always look for a phosphate free stain remover.

If you have a white bottom pool and have staining you can use United chemicals stain treat or super stain treat. They are the best product on the market for removing stains. If you want to test first to see if it will work, buy a spotting back and place it on the stain. If the stain comes off then the product will work.

Note: Also keep your pH and Alkalintiy in balance and it will also help reduce staining. pH should be 7.2 to 7.6 ppm and TA should be 80 to 120 ppm.