It is not uncommon for fiberglass steps in swimming pools to develop stains over time. I have seen them in a variety of colors. They can be caused by different types of algae, and in some cases can be the result of having metals in the water such as iron. Regardless of the cause, it is possible to clean steps and restore their original color. In this post, I will describe some of the more common stains and what causes them, and offer some advice on how to remove the stains.
If you have had a pool for some time, then you have probably experienced this problem first hand. For those who have only had their pool for a short period, then you may have been alarmed at the first sight of these stains on your steps. Rest assured that these stains can be removed in a number of ways depending on what caused them. Even though some stains are not green, they can be caused by algae. It is important for you to know that algae can appear in a variety of colors, even though many associate algae with the color green. Depending on the type of algae, it may be yellow, pink, brown, or black. Regardless of the type of algae, there are ways to clean them. Before you go about cleaning algae off the step, you need to make sure you also work toward keeping the algae from coming back.
You will want to shock the pool and add the appropriate amount of algaecide. I want to point out that black algae is typically more difficult to get rid of. You will want to take the same steps as with the other types of algae, however, you will need to get an algaecide that is specifically formulated for killing black algae. Additionally, you will want to scrub all of the areas of black algae with your pool brush. Black algae has a hard outer layer that will help to protect it from the algaecide and you will need to break through that layer with the brush to allow the algaecide to effevtively kill it. Once you have treated the pool for the algae, you are ready to tackle the steps. Typically, once the chlorine and algaecide begin to work, the algae stains on the steps should just scrub off with a brush. If that does not completely clear the algae, you may want to look into some products that are available for cleaning steps.
The other cause of step stains in a pool is the presence of metals in the water. These can leave yellow, or rusty colored stains on the step, which are more visible on white steps. In some cases, these stains can be removed by using a brush, but that does not always work completely. I have found that stubborn pool step stains can be adequately removed by using a Mr. Clean Magic Eraser. This actually works rather well. Depending on the severity of the stain, you may have to look into specific product for cleaning metal stains off of pool steps. Check out this video posted on YouTube on how to remove metal stains from a fiberglass step using a specialty product https://www.youtube.com/watch?v=ufySSK5grWw. The easiest way to keep stains from getting out of hand is to stay active in keeping the steps clean and maintaining your pool water chemistry. With properly balanced pool water, these types of stains should not be a problem.
For more information on algae in pools and other pool water problems check out my post titled “Pool Water Problems” and feel free to look at my other posts which cover a number of swimming pool related topics. I am always open to any feedback you may have regarding any of the topics I post about, so feel free to comment.