Swimming Pool Guides & Reviews by Certified Pool & Spa Operators
How to Recognize and Eliminate Swimming Pool Stains
Here’s Everything You Need To Know
There are a lot of joys to pool ownership, but there are also some annoyances too. One of which is dealing with pool stains. This is a common problem which you must deal with during your pool maintenance routine.
First, you must identify where the stain is coming from. Then you must apply the appropriate method for removing it.
Below are the two main types of pool stains:
Organic stains: Do you have organic debris near your pool surface? This type of debris could be leaves or berries from nearby greenery. If the organic debris stays in your water for too long, it’ll leave organic stains on the pool surface.
Rusty or Metallic Stains: If copper pipes are connected to your pool, then corrosion can be introduced into the water and leave rusty stains on the surface. The same thing can happen with well water too.
You can tell the two stains apart by their color. Sometimes there is even a combination of colors too. These colors can help you identify the cause of the stain.
Green & Brown : Stains with green and brown colors are probably organic stains. Any kind of nearby plant matter, such as leaves, likely caused it.
Red & Blue: Berries with vibrant colors probably caused your pool stains if the colors are red and blue. See if there are any bushes nearby with growing on them.
Black, Blue, & Green : Do you see stains with black, blue, and green colors? If you don’t see any greenery or organic matter around, then copper is likely the reason for the colors.
Red, Green, & Brown : Iron is the likely reason for your stains if the colors are red, green, and brown.
Purple, Brown, & Black: Manganese caused these darker stain colors.
If you’ve figured out the likely cause of your pool stain, the next step is to confirm your suspicions. When you believe that you have an organic stain, add a little bit of chlorine to it. The stain should go away fast. However, metal stains can be removed faster with ascorbic acid (vitamin C). You can find this acid in citrus fruits, but it is easier to purchase the ascorbic acid powder and put that on the stain directly. The stain should at least lighten up, if not go away entirely.
Removing Pool Stains
You can remove organic stains by adding a lot of chlorine to the pool water. Once you do that, you can brush the stains right off. You’ll need to test the alkalinity level and pH level of the water first. The pH level needs to be anywhere from 7.4 to 7.6. The alkalinity level needs to be anywhere from 100 ppm (parts per million) to 150 ppm. Test strips are what you test the water with.
Bigger organic pool stains will require 3 lbs. of calcium hypochlorite per 10,000 water gallons, which is triple shock treatment. Dusk or nighttime is the best time to start the shock treatment process.
After the shock is over, brush the stains to weaken them. Keep the pool water circulating for a minimum of 8 hours. Brush the stains at different times throughout this 8-hour period. Keep a high amount of chlorine in the water until you don’t see the stains anymore.
It is tougher to remove metal stains, but it can be done. First, take a sample of water from your pool and have it tested at your local pool store. They can determine which metals are in the water and what their levels are.
Based on this information, purchase the appropriate metal stain remover and use it on the metal stains of your pool. Follow the instructions on the packaging for better guidance. Brush the stains throughout the process.
Prevent Future Stains
It is critical that you prevent pool stains. That is why pool maintenance is important. Organic stain prevention is as simple as maintaining the proper sanitizer levels in your pool water. Therefore, make sure you have enough chlorine in the water.
You must also balance the alkalinity level and pH level too. This helps ensure that the chlorine does its cleaning job well. Make sure you vacuum your pool regularly with an automatic cleaner or manual cleaner. Skim the surface to remove floating debris.
To prevent metal stains, you must regularly test the water to see if there are traces of metals in it. If you find out there is metal in the water, a metal sequestrant can stop metallic debris from attaching itself to the surfaces of your pool water in the future.
If you have copper stains in the pool, then it is probably from low levels of pH. This means you have acidic water. Copper pipes corrode from acidic water. Because of this, balance the pH levels accordingly.