Remove Pool Stains: Above Ground Pools Guide


We all look for an escape from the summer heat, and what could be a better one than a nice, cool pool? Still, a dirty pool can keep people out of it and can put a damper on the fun. This is why you need to remove pool stains whenever you notice them. They require regular maintenance to keep them out, but they occur naturally in pools. 

Usually, removing the stains will be fairly easy. But, these spots can be really hard to remove and you will have to do a bit more than just scrubbing. Keep reading to find out how to diagnose a pool stain and how to clean stains on the bottom of the pool as well as on walls. 

How to Remove Pool Stains – Guide 


Classifying the cause can be done just by looking at the color of the pool stain. Colors that appear in pools may vary and they may have different colors. The right treatment for your problem will be easier to determine if you identify the color. A removal plan needs to be accessed for each stain and you can do that if you know the cause. 

Organic and metal-based stains are the two main stain categories. Both can cause a variety of stain colors. Usually, they are brown-black-purple, pinkish-red, green-brown-red, blue-green-black, red-blue, – and green-brown. Go to your pool right now and check what color is your stain. 

The floor of your pool will be, in most cases, affected by organic stains. Some of the common causes are worms, algae, dead animals, berries, leaves, and other organic waste. If you notice any of these in your pool, make sure you remove them right away. If you don’t do so they will start decaying on the floor of your pool and cause stains. Still, it will be very easy to remove pool stains caused by organic matter. 

These stains are usually brown, green, or purple-blueish. If you notice any organic waste in your pool, the stain is most likely caused by it. Use a small amount of chlorine directly on a stain if you suspect it is organic. Then let your cleaner get rid of it, but it will dissolve on its own quite fast too.  

On the other hand, metal-based stains can be a bit harder to remove. The main causes of this type of stains are usually corrosion from copper pipes and well water. Even major stains can form if a copper piece that’s only big as a penny gets oxidized in the pool. Other types of metal that can get into your pool are iron, manganese, and rust. 

You can be sure that metal is causing stains in your pool if you notice that the pool wall below a ladder has rust-colored stains on it. If this happens, your ladder will probably have corrosion too. Other places where you should check for discoloration is under the lop of the pool and around the drain. 

Knowing which metal is causing stains in your pool is mandatory. Copper will result in dark purple, black, teal, green, or blue stains. Iron stains are usually greenish-brown, gray, or rusty brown. Well, water usually contains manganese, and stains from it can be purple, brownish-black, or pink. Calcium can also cause stains and they will show as white crystals. 

If you want to learn how to clean stains on the bottom of the pool properly, then you need to be able to identify what’s causing the stain and then use the right treatment for it. 


Sometimes, leaves or algae can cause greenish-brown colored stains if they’re left on the pool floor for some time. You need to remove them as part of the treatment. As already mentioned above, it shouldn’t be a problem for you to remove pool stains caused by organic waste. But, if you don’t do it on time the water in your pool will start to have a light-brown, dull color that you won’t be able to clean even with the best filters

To make sure organic debris is regularly cleaned you can use a pool skimmer. Do this more often if you have trees around your pool since fruit, branches, and leaves from it may drop into the water easily. Pool vacuum hoses can be used for removing the debris from the bottom of your pool. 

If you don’t clean the stains they may become permanent. In this case, you’re going to need to drain the water and clean your pool with acid. Still, don’t let this become your routine since acid will certainly strip off a thin layer of the pool. 

You can also try an enzyme shock treatment or shocking your pool with chlorine.  Heavily chlorinating the water will allow you to address organic stains easier too. 

When it comes to metal stains the first thing you should try to do is to get your hands on one of those metal removal products that you can place in the skimmer basket. They usually come in different sizes so you shouldn’t have too much trouble finding the right one for you. Also, check the packaging for the strength of the product so you know which one will work the best. 

Make sure that your pool equipment and machines are turned off while you’re removing metal stains. This includes ozone generators, UV systems, generators, and chlorinators. Even your pool heater shouldn’t be in contact with water while you’re cleaning. 

The chlorine levels need to be between 0-2 per 1m. This is because you will use less ascorbic acid to get rid of the stains if your chlorine levels are low. If you’re using an algaecide make sure to follow the instructions on the box to avoid adding too much if your pool is not big. Lower chlorine levels allow algae to spread, so that’s why you should add it.

Use ascorbic acid to remove the stains. You can find these at your local shop, but you can also make your version Just crush a few vitamin C tablets and use that for cleaning the stain. Rub it and then wait for a couple of minutes, then check whether there’s an improvement. 

Once you remove the stains from the pool the last thing you want to do is to restore a healthy chemical balance. Monitor hardness, alkalinity, and pH levels to check whether they’re in an appropriate range for the size of your pool. Turn on ozone generators, UV systems, chlorine generators, and automatic chlorinators back on. To ensure that metal stains won’t reappear use a metal eliminator in the skimmer basket. 


Q: What causes brown stains in swimming pools?


Brown stains in swimming pools are usually caused by a high concentration of iron. Iron levels needs to be under 0.2 mg/L if they go above air oxidation will cause iron oxides to build up and you will get brown stains. Brown algae are the second possibility for brown stains, but they are less common. 

Q: Will pool shock remove stains?


Yes, in most cases pool shock will remove stains from the pool. But, after shocking the pool you will have to brush it up a bit to remove the stains completely. Organic stains are easily removed by this “bleaching” technique. Use chlorine shock directly on the stain to get the best results.  

Q: How do you get stains out of pool plaster?


To clean the stains out of plaster pools you will need an acid wash with muriatic acid in it. Keep in mind that by using this type of acid you are going to remove a thin layer of plaster. So, don’t do this too often to avoid getting the plaster damaged too much. 

Q: How do I remove tannins from my pool?


To remove tannins from your pool you will need to do a few things. First, increase the circulation of the water in the pool. Use a chemical test kit to test for chlorine levels in the water and use a shock treatment if needed. The tannin stain should dissolve completely after a couple of days.

Globo Surf Overview

Hopefully, this article will help you understand how to clean stains on the bottom of the pool and its walls. The process is not too complicated, but it will certainly take you a few hours. Don’t rush, take your time, do chemical tests, and get rid of the stains easily!

More Pool Reviews:

Globo Surf
My name is David Hamburg. I am an avid water sports fan who enjoys paddle boarding, surfing, scuba diving, and kite surfing. Anything with a board or chance I can get in the water I love! I am such a big fan I decided to start this website to review all my favorite products and some others. Hope you enjoy!