How can you get rid of yellow stains caused by adding Guardex Hy-Cal to your inground swimming pool?

Check your local, reputable, pool or service store for "Jack's Magic" Products. They are the best for any type of stain removal. You will first need to perform a stain test on your pool to determine which product you will need to use. Do not, and I repeat, do not let anyone just sell you one of the products without performing the stain test. This is a must in order for the product to work correctly. If you need to contact the company prior to purchasing the products please do so. They are very knowledgable and may be able to locate a dealer in your area.