7 Common Pool Problems and How To Diagnose & Fix Them

Kenneth Wilson

It’s nice to have your own pool - you can swim anytime, have privacy, and enough space to safely play or do laps. But it’s not all fun and games being a pool owner. When problems arise, you can’t just pick up your stuff and leave. 

To make owning a pool easier, you should know what the common pool problems are before it occurs in your pool. So here is a guide that shows you how to spot and fix seven pool problems that can happen to any pool owner.

Clogged Filter

An important piece of equipment that keeps your pool clean and pristine is the filter. That’s why it is important to regularly check and maintain it. 

One of the most common filter problems is clogging. When it is overused, debris such as leaves, bugs, dirt, and other organic waste can clog up your filter and reduce its effectiveness. Not only does a clogged filter affect the filtration system, but it may also disrupt your circulation system.

Other than manually inspecting the filter, you can determine if it’s clogged by looking at your pool water. In most cases, the pool will have more dirt and debris than usual if the filter is clogged.


To fix a clogged filter, remove the filter from the system and clean it. Cleaning your filter depends on what filtration system you’re using. Most of the time, you can spray the filter with a hose until it is clean. But there are filters, such as sand filters, that have a specific process for cleaning. 

The other types of filters used by pool owners are cartridge filter and diatomaceous earth or D.E. filter.

Note: After cleaning your filter, it’s best to clean your pool as well.

To prevent your filter from clogging, check your filter often. You should also regularly clean your pool and clear out floating debris with a skimmer net as soon as possible. 

Cracks and Leaks

It is common to find cracks in your pool due to the flexing or shrinking of the cement. These small cracks are called crazing or check cracks. Larger cracks, which are called structure or major cracks, occur when there is soil movement, hydrostatic pressure, settling, or soil conditions exert strong pressure on the pool shell - whether if it is made of concrete, gunite, or fiberglass. 

Crazings normally pop up and will rarely cause the pool to leak. On the other hand, structure cracks may lead to leaking. When vinyl liners get holes, leaking may also occur.

Pools with vinyl liners, don’t get cracks but tears. Pool tools, equipment, vacuum, dogs’ nails, and other sharp objects can easily cut the liner. Even if you are careful, pool chemicals, the sun, and time will eventually ruin the liner.

To determine whether you have a leak or if it’s just evaporation, pools tend to lose half an inch of water in 24 hours from evaporation. If you’re losing more than half an inch, you probably have a leak.


To repair vinyl liners, vinyl patches can be used to stop the leaking. Another option is to replace the entire liner, which would be expensive.

To fix pool shells, you can apply plaster on the crack or get a plastering company to fill in the cracks with plaster slurry. This is the most commonly used method because it can be done underwater. Unfortunately, this is not a permanent repair nor can it stop the crack from reappearing. 

If you don’t mind draining the pool, caulk or epoxy can also be used to repair cracks. Epoxy and carbon fiber staples can be a permanent solution but it will leave a grey streak on your pool finish.

It’s difficult to find a permanent solution since we cannot fix soil movement, settling, and other conditions that cause cracks. After sealing a crack, it can always reopen or a new crack may appear.

Since we cannot do anything about these conditions, you can reduce the chances of cracking by making sure not to leave your pool empty for too long when you drain it. 

If you’re just planning to get a pool, make sure that it is properly installed and has a steady foundation to reduce the chances of cracking. For example, some contractors put more steel in the foundation to avoid this problem.

Stains and Colored-Spots

It’s annoying when you just finished cleaning your pool and it still looks dirty. If this happened to you, you probably have stains and colored-spots present in your pool.

Pools can either get stains from organic waste, minerals, or metals. Here are the possible sources for your pool stains and what color they might be:

  • Leaves (greenish-brown)
  • Berries (reddish-blue)
  • Algae, worms, and other animals (depends)
  • Copper pipes (dark blue-green)
  • Iron (reddish-brown with green)
  • Manganese (dark brownish-purple)
  • Rust from a crack in the foundation, wall, or fittings (orange)


There are several ways to get rid of organic stains. You can use stain remover chemicals, stain eraser, or pumice stones (for in-ground pools). But if the stain has spread all over your pool, a great way to get rid of it is by shocking your pool. Brush the surface during the process to get rid of the colored-spots. For stubborn stains, apply granular or powdered shock directly on it.

Note: Pre-dissolve the powdered shock before applying on vinyl-lined pools.

For stains caused by minerals or metals, you first need to determine what is causing the stain. After, find a suitable metal stain remover to treat your pool.

If none of these methods work, you may need to hire a contractor to acid wash, resurface, or replace the liner of your pool.

To prevent organic stains, you just need to regularly clean your pool. Get rid of floating debris when it lands on the surface. Aside from the pool, you also need to take care of the plants, trees, and bushes surrounding your pool. Invest in a pool cover or hire a contractor to build a pool enclosure.

The best way to prevent metal stains is to regularly test your water for any metals present in your pool water. For example, copper stains occur when the pH level is lower than 7.2. When the pH is low, the water becomes acidic and corrodes copper, which will then leak into the pool. 

Always balance your pool water chemistry to prevent both metal and organic stains. Make sure that your chlorine, pH level, and total alkalinity are within the ideal range.

Rough Surface

For concrete pools or pools with plaster, a problem you may have to face is the pool surface getting rough due to adding too much chlorine or chemicals.

Even if you add the right amount of chemicals, and regularly clean and maintain your pool, the surface of the foundation will get coarse because of usage and time. Aside from injuring swimmers, this will make it easier for stains to develop in the pool if left untreated. The only good thing about this is it doesn’t affect the structure of your pool. 


One way to solve this problem is to sand the plaster to make it smoother and look better. First, you need to drain the pool and then find an 80 grit, 120 grit, 240 grit, and 600 grit wet/dry sandpaper and a sanding block. You will need to sand it four times with the sandpaper in ascending order of grit number. After sanding, rinse the surface and then fill the pool.

If sanding doesn’t fix the roughness, you will need to hire a contractor to resurface your pool.

You can prolong the smoothness of your pool surface by regularly testing for the calcium level of your pool water. If you let it get too low,  the water will get this mineral from the concrete walls and floor. The concrete will get weaker when the calcium is leached off, making the surface rough and pitted.

Pool Water Foaming

If you notice your pool forming foam, it may look dangerous, but it is not. This usually occurs when the water is thick, which creates bubbles. The circulation system fills these bubbles with air and then produces the foam.


You should also watch out for products that we use or apply to our bodies. Foam can also be caused by hair products, lotions, makeup, soap, and detergents. 

If you are opening your pool after months of not using it, you should probably expect the foam. The chemicals from winterizing the pool are gassing off and creating a chemical reaction with the chemicals you are adding to open the pool.

When opening your pool, take note that if there are no algae to kill, the algaecide will create some foam. Don’t worry, it will eventually disappear after some time.


After not using your pool for months and using an opening kit, you can get rid of the foam by shocking your pool. You should also make sure that the calcium level is balanced because the foam will form if it is too low.

If your pool is well-maintained and there is still foam, the problem might be your pool equipment. If there is a crack in the seals, lids, o-rings, and other parts in your system, this will create foam. Regularly check and replace these pool parts, if needed.

Eye and Skin Irritation

If your eyes or skin are burning after swimming, it’s probably because your pool water chemistry is not balanced. When the pH level is below 7.5 or above 7.8, the pool water will burn our eyes and skin. 

This applies to chlorine levels as well. Having too much chlorine may prevent algae, but it will irritate our skin and eyes. If the chlorine is too low, this will result in the build-up of chloramines. Chloramines are a combination of chlorine and nitrogen from body oils, sweat, or urine. Aside from skin and eye irritation, it also produces an unpleasant odor.

You may not mind this problem since the irritation stops after getting out of the pool, but it’s a sign that your pool water needs to be balanced. If you don’t, algae will grow in your pool.


The pH level should be between 7.5 to 7.8. Apply soda ash or pH increaser if it’s below this range. If it’s above, use muriatic acid or pH decreaser.

To maintain your chlorine’s effectiveness, the Free Chlorine or FC level should always be between 1 to 3 parts per million. FC level is the current chlorine level that is sanitizing your pool water. Combined Chlorine or CC level is used chlorine that is present in the pool but it’s not effective anymore. CC level should be kept below 0.2 parts per million.

Mineral Scaling

If you notice white or white-grey scales appearing in your pool, it’s probably due to the build-up of inorganic materials in the water. Once again, this happens because your pool water chemistry is not balanced.

Scaling is the build-up of inorganic materials, such as calcium carbonate or calcium silicate, on pool shells made out of plaster, fiberglass, stones, and ceramic tiles. The white scales are caused by carbonate, while silicate creates white-grey scales.

It’s better to have plain white scales than ones tinted with grey. If it’s silicate, this means you may have a leak in your pool and there are probably several areas infected. This mineral takes longer to form so there was more time for it to spread before you were able to notice it. On the other hand, carbonate is easier to remove and doesn’t take as long to form or notice.


The process to remove carbonate and silicate are similar, but it will only be easier to clean carbonate-made scales. Use calcium remover and scrub the area with scales. You can also use a pumice stone to get rid of the affected areas. 

To avoid scaling, make sure that the calcium level is between 200 to 400 parts per million. If it’s higher than 400 parts per million, more mineral deposits will form. One way to lower the calcium level is by using the dilution method or reducing the pool water and replacing it with fresh water. You can also opt to add sequestering agents.

You should also make sure that the pH level and total alkalinity are within the ideal range. To put it simply, regularly test your water chemistry and properly balance it.

Don’t forget, the pool should also be regularly cleaned and maintained. To prevent scaling, it’s important to always brush the pool floor and walls.

Kenneth Wilson
November 12, 2019
Yard & Garden

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

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