Diagnose the Stain
The first step in removing a pool stain is to diagnose what kind of stain it is. Pool stains can be caused by various sources including rust and metals; or organic materials such as mud, algae, leaves, or berries. Different types of stains require different treatments. The best way to diagnose a pool stain is by looking at it's color. Stains that are caused by metals tend to be reddish-brown and have a rust-like appearance. The most common metals that cause pool stains include copper, manganese, or iron. Iron stains can look rusty and red, brown, and greenish. Copper stains are usually bluish green, and manganese will cause purple or brownish-black stains. If there is evidence of organic matter and the stains appear green or brown, the culprit is likely leaves, mud, or other plant matter. Conversely, brightly colored berries or seeds will leave stains that appear red and blue. Once you have an idea of what is causing the stain, it is time to test and treat it.
These stains typically occur when debris such as algae, mud, leaves, mud, or dead worms sink down and settle on the bottom of the pool. While they may make your pool look dingy and dirty, they are relatively easy to remove. If you suspect the stains in your pool are the result of an organic material, try applying a small amount of chlorine directly on the stain. Organic stains will dissolve easily and can be brushed away using a soft head brush. If there are multiple organic stains in the pool, it is best to shock your pool and let it sit overnight. Next, you will need to brush away the stains and keep chlorine levels higher in the pool until the stains are dissolved.
Metal Based Stains
These stains can be caused by corrosion from copper pipes or well water. A small amount of oxidized copper can cause large stains in the pool. These types of stains often occur around ladders, stairs, drains, and under the lip of the pool. In order to treat these stains, you will need to know exactly which type of metal is causing it. This can be determined through a water sample. Take the sample to your local pool care store to determine what the problem is and they can recommend the right chemicals and additives to treat the problem. You can also use a citrus based stain remover to move the process along. If these solutions do not solve your problem, you may need to seek professional help.
The best way to prevent stains in your pool is through proper care and maintenance. This includes testing your water regularly to ensure proper pH and chlorine levels. Improper water balance can cause stains to occur. Furthermore, be sure to remove any debris from your pool and vacuum the floor on a regular basis. Routine cleaning and water maintenance is vital for stain prevention.