7 Easy Ways to Clean Pool Grout Like a Pro

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Tile has the ability to add a feel of luxury to any pool.  Pools may be fully tiled across the walls and floors, or may just have a tiled border around the waterline.

Similar to tiles that you may find in your house, tiles in a pool have grout between them.  The grout serves to provide a bond between tiles and also leaves a cleanable surface.

While grout provides an important function for the tiles, it can also be used to enhance the overall aesthetic of the pool.  Tile patterns can be made to visually pop if using a stark contrasting grout color.  Or, grout can remain largely unnoticed by choosing a color that is similar to the tile.

With the beauty of tiles also comes the TLC required to keep them looking fresh.  Dingy tiles and grout can not only detract from the overall appearance of the pool, but it can also hint at overall cleanliness of the pool –i.e., if your grout has turned green, this could indicate similar growth in the pool water.

This article will explore how to clean pool grout and tile using seven methods:

1 – Scrub it
2 – Vinegar and warm water
3 – Baking soda and hydrogen peroxide
4 – Chorine tablet
5 – Muriatic acid and water mixture (“Acid Wash”)
6 – Commercial cleaner
7 – Use a pressure washer

How Does Pool Grout Get Dirty?

While it may seem like grout in the pool should stay naturally clean as long as the pool water is clean, that’s not hardly the case.  Understanding what’s causing your grout to become dirty can help identify appropriate cleaning methods.

Grout often has small pores that are hardly noticeable to the naked eye.  These small crevices are great hiding spots for algae and dirt which can eventually cause the grout to appear dingy.  

Additionally, pools should generally have between 180-220 ppm of calcium in the water to achieve the appropriate hardness level.  If the pool has elevated levels of calcium, it can accumulate on the surfaces of the pool leaving a hard white residue –the longer this residue remains in place, the harder it is to remove!  

Types of Grout

Before jumping into cleaning your pool grout, it is necessary to understand the two primary types of grout used in pools. The type of grout can impact the way that you clean it.

Epoxy Grout

Epoxy is generally considered the crèm de la crèm for grout, whether in a pool or elsewhere around the house.  

Epoxy provides excellent stain resistance and is very strong with less susceptibility to cracking.   It is waterproof with excellent resistance to harsh weather conditions, including extreme cold.  These characteristics make it great for use in pools, and easier to keep clean.

If there are any downfalls to epoxy grout, it’s that it can cost more than twice that of other grout types –this can add significant cost if tiling an entire pool area.  Installing epoxy grout can also be more time-consuming as it requires smaller batches to be used due to its quick setting time.  

Cement Grout

Cement grout is an affordable and effective option for pool tile.  Although epoxy grout is often viewed as superior, cement grout is commonly used with success.

Cement-based grouts are offered in unsanded and sanded options, depending on the joint size between tiles.  Cement grouts often provide more color selection than epoxy grout, and are also easier to install due to longer working times.

All good things considered, cement grout is more susceptible to staining due to its porous nature.  Mold and dirt is more likely to grow within the grout, meaning that it may require more frequent cleaning to keep it looking fresh.

Since cement grout is not naturally waterproof, a sealer is may be applied when the grout will be used in high moisture environments (example: pools).  Sealers may wear over time and could require re-application periodically.

How To Identify What Type of Grout is Installed?

If you inherited an existing pool and are unsure what type of grout is installed, a few steps can help you figure it out.  

If the grout above the waterline remains glossy even when dry, there’s a good chance that it’s epoxy.  However, since sealed cement grout can also have a glossy appearance, additional investigation is needed.

If the pigment within the grout appears a bit inconsistent or splotchy, this is more likely an indicator that the grout is cementitious.  Epoxy grout color is typically consistent throughout.

An acid test can also be performed by applying a small amount of muriatic acid to a section of the grout.  If the grout bubbles or degrades, this would be a sign of cement grout.

If you’re trying to determine whether the grout is sealed or not, dab a bit of water onto it.  If the water is absorbed and the grout darkens, this would indicate that the grout is probably not sealed (or the sealer has degraded).  If the grout does not change color, it likely signifies either epoxy grout or sealed cement grout.

How to Clean Pool Grout

Before starting to tackle the grout, it’s a good idea to remove debris that may be floating in the water.  Cleaning the grout will be easier if you’re not having to work around leaves, grass, bugs, etc.

If you’re focused around cleaning grout at the water line, it may be helpful to drop the water level slightly.  Many of the cleaning techniques are easier to use above water rather than below water.

It’s also best that you test any of the cleaning methods in an inconspicuous area to ensure no damage is being caused to the grout.  This can be especially true if you’re unsure as to the type of grout that is installed or whether it has been sealed (waterproofed) –some cleaning methods may not be suitable for specific grout.

1 – Scrub It

A simple scrubbing of the tiles and grout can go a long way in removing visible dirt and mildew. 

Your nylon pool brush may be the perfect tool for this job, and can be easily used for grout that is both above or below the water line.  For tight areas, a toothbrush is also a great option.

Gently scrub in a circular motion across the grout and tiles, working across a few feet at a time.  Splash water onto the grout above the water line while scrubbing to help with the cleaning process.  

The bristles can dislodge dirt from small crevices that may be hidden within the grout.  Some elbow grease may be needed for grimier spots.

Although it may be tempting, avoid using a wire-bristled brush as it could damage both the grout and tile surfaces.

Pumice Stone for Stubborn Areas

If you have residue or calcium deposits on your grout that are too strong for your nylon brush, consider adding another tool to the arsenal: pumice stone.

Pumice stones provide a more aggressive means to grind down stubborn deposits from your grout and tile.  Simply wet the stone with water and rub it against the surface for cleaning.  You may need to angle the stone to fit into the grout joints for cleaning.

The stone can be used for areas both above and below the waterline. Just ensure that when used above the water line, the stone is kept wet to avoid scratching the tile.

Over the course of use, the pumice stone will wear down.  If you’re cleaning a large section of your pool, prepare to go through at least a couple of the stones.

Rotary Brush to Save Your Arms

Another option for stubborn residue on tiles is the use of a nylon rotary brush.  The brush can be attached to a cordless drill which can save your arms from repetitive scrubbing.

The downfall with this option is that the drill can’t be submerged in water, so this will require draining of the pool if trying to work on tiles below the normal waterline.

2 – Vinegar and Water

If scrubbing alone isn’t enough to rid your pool grout of dirt and build-up, it may be time to employ one of the most trusted cleaning solutions used around the house: vinegar and water. 

A vinegar-water mixture contains enough acetic acid to effectively remove grime and calcium deposits with less risk of damage compared to more aggressive cleaners.  It’s also safe enough to handle without risking personal injury.

This mixture can be used to clean pool grout that has been sealed, including epoxy grout.  If you have unsealed cement grout, you’ll want to avoid using the vinegar-water mix as it could be absorbed resulting in eventual weakening of the grout.  

To use vinegar and water to clean your pool grout, follow these simple steps:

1) Ensure the water level is below the section of grout to be cleaned; drain as needed. 
2) Mix a 1:1 ratio of vinegar and water into a spray bottle.
3) Spray the solution onto a section of grout.
4) Allow the mixture to soak for about 5 minutes.
5) Scrub the grout with a medium bristle brush.
6) Rinse the grout with water afterwards to remove the vinegar mix.

While a vinegar-water mixture is often a great option to try, it may not always be enough for build-up that has been accumulating over a long period of time.  

3 – Baking Soda and Hydrogen Peroxide

Baking soda with hydrogen peroxide is another homemade cleaner that is commonly used around the house to remove stains.  It can also be used in beautifying your pool grout.

Unlike many other cleaning mixtures, baking soda and hydrogen peroxide is generally suitable for all types of pool grout –whether sealed or unsealed.

The combination baking soda and hydrogen peroxide generate an oxygenated bleach, which is effective for fighting stains and calcium build-up on grout.

Although the standard 3% concentration of hydrogen peroxide is safe for skin contact, you may want to consider wearing gloves to prevent irritation from prolonged exposure while cleaning.

Here are a few easy steps in using baking soda and hydrogen peroxide for your pool grout:

1) Ensure the water level is below the section of grout to be cleaned; drain as needed.
2) Mix a 2:1 ratio baking soda and hydrogen peroxide in a container. 
3) Using a small medium bristle brush –such as a toothbrush– spread the mixture onto the grout.
4) Allow the mixture to sit on the grout for about 5 minutes.
5) Rinse the mixture off the grout.  

If you find that stains persist after using baking soda and hydrogen peroxide, you can repeat the process additional times as needed.  Otherwise, you may want to consider a different method.

4 – Chlorine Tablet

The thought of using a chlorine tablet to clean pool grout may seem a bit too simple.  But, if you have organic build-up –such as algae– on the grout, a chlorine tablet can be one of the best options.  

For this method, all you need to do is rub your typical chlorine tablet along the grout line.  A bit of pressure may need to be applied in order to transfer the chlorine onto the grout surface.  The grout should lighten up fairly quickly once the chlorine has been rubbed on.  

This method can be used for grout both above and below the water line.  For grout above the waterline, you should rinse the chlorine off afterwards.

5 – Muriatic Acid and Water (“Acid Wash”)

Before considering use of muriatic acid, know that it is a very strong acid that can be hazardous to people, pets, plants, and surrounding objects.  Use gloves and eye protection when handling it, and ensure adequate ventilation to avoid the fumes.

Muriatic acid is often used for industrial purposes, but can also be an effective cleaning agent when properly diluted with water.  It is a much stronger acid than that of vinegar which makes it a more aggressive cleaner.

A muriatic acid and water combination –also known as an acid wash– can dissolve away grime and calcium from the pool grout.  But, it’s important that the ratio of muriatic acid is not too high as it could actually eat away at the grout itself.  

Similar to vinegar, you won’t want to use this with unsealed grout, as it could be absorbed resulting in damage.

If you’re comfortable taking necessary precautions with muriatic acid, you can follow these steps for cleaning your pool grout:

1) Ensure the water level is below the section of grout to be cleaned; drain as needed. 
2) Have a hose or bucket of clean water on standby in case muriatic acid spills in an unintended spot.
3) Equip your protective gear: eyewear, gloves, respirator (if in a closed space).
4) Create a 1:16 acid-water mixture:
-Fill a plastic bucket with one gallon of water.
-Slowly mix one cup of muriatic acid into the water. (Always add acid to water, never add water to acid).

5) Carefully transfer the acid-water mix into a spray bottle.
6) Spray the acid-water onto the grout, and allow it to sit for a few minutes.
7) Scrub the grout with a small medium bristle brush.  
8) Rinse the acid from the grout.

Muriatic acid is often used to help reduce pH of a swimming pool.  After rinsing the acid from the grout, you may want to check your pool’s pH to ensure this cleaning method didn’t cause a drop in pH. 

Once finished with the acid-water mixture, you can simply dump it into your pool if you’re in need of lowering the pool’s pH.  Otherwise, contact your municipality to receive instruction on how to safely dispose of it as it’s not safe to go into your home’s drain.

6 – Commercial Cleaner

If you’ve found that scrubbing with homemade cleaning mixtures hasn’t been able to restore your pool’s grout, it may be time to consider commercial options.  

Your local home improvement stores or on-line retailers have large selections of various cleaners.  The commercial cleaners may be marketed for specific purposes, such as dirt removal, calcium removal, etc.

These cleaners typically come in the form of either a spray or a paste.  Depending on the type of cleaner, they may also require scrubbing in order to be most effective.

If you’re thinking about using a commercial cleaner while the pool still has water in it, it’ll be important to ensure that the cleaner won’t cause a dangerous swimming environment afterwards.  Some of the cleaners may have nasty chemicals that people should not swim in.  Contact the manufacturer if the label does not indicate whether it’s safe in pool water.

Once you’ve purchased the cleaner, it should be as simple as following the instructions on the container!  

7 – Use a Pressure Washer

Using a pressure washer can be a great alternative to cleaning the pool grout compared to manual scrubbing.

When considering this as an option, more pressure is not always better for grout and tile.  A simple pressure washing activity can quickly turn into a big mess if it starts cracking tiles and removing chunks of grout.

It’s best to aim for a pressure of 2000 psi or less when utilizing a pressure washer for grout cleaning. 

If your washer does not have a way to reduce the pressure from the engine, you may be able to choose a wider nozzle tip to help soften the impact of the water.  Holding the nozzle farther away from the grout will also help prevent damage.

Testing in a small section of grout is highly recommended before running wild with the washer.

While washing, slowly move the wand back and forth across a section of tile.  Try not to stay in one spot for too long as this will increase the risk of damage.

While it’s ideal to expose the tiles so that they are above the water level, it is possible to pressure wash under water.  For obvious reasons, the engine will need to remain outside of the water, but the hose and wand can typically be submerged underwater.  

If pressure washing the grout underwater, you may need to hold the nozzle a bit closer to the grout in order to effectively clean.  The primary risk with this method is if grout or tile is damaged, it may not be possible to repair without draining the water.

Preventative Care for Grout

After restoring your grout back to new through all your hard effort, you probably won’t want to repeat it again for a long time.  Routine upkeep of your grout can help avoid intensive cleanings.

A simple way to help keep your grout clean is routine scrubbing with your nylon pool brush.  Aim to scrub all the walls and floor at least once a week to keep grime and algae from accumulating.

Maintaining appropriate chemistry in the water is also key in keeping your grout in top shape.  Ensure your pH, alkalinity, and sanitizer are at appropriate levels.  Keeping hardness within appropriate range (180-220 ppm) is important in preventing calcium deposits on the grout.

If you start noticing white calcium deposits on your grout or tile, it may be best to tackle it sooner rather than later.  As it continues to build up it will only become tougher to remove down the road.

Final Takeaway

Cleaning grout is not a glamorous job, but it’s an important part of pool care. When deciding on a cleaning mixture, remember to factor in the type of grout in your pool to avoid costly damage.  

If you find that after attempting several different cleaning methods the grout in your pool is still not up to par, don’t lose hope.  It may be worth considering having a pro tackle the job as they have additional equipment that can restore the grout.  

Once you’ve restored the grout to its original beauty, simple preventative care can limit how often it needs to undergo the more intensive cleanings.  Regular scrubbing with your pool brush and proper water balance will go a long way in keeping dirt and algae at bay.  

After mastering the art of cleaning grout, you can look ahead at the easier task of cleaning mold from pool toys. This will ensure you’re all squared away for summer fun at the pool!

Happy Scrubbing!

2 thoughts on “7 Easy Ways to Clean Pool Grout Like a Pro”

  1. Hi, Thank you for all your knowledge about grouts. I’m having a problem. We grouted our pool with Bostik Dimension Rapidcure grout. It says is a urethane grout. They recommended it to avoid efflorescence. Now I have a grout that is full of black mold. It’s very hard to clean because of the micro particles. when I brush the grout I can see the micro particles (glass???) floating on the water. I think every time I brush the grout I am destroying it. How should I clean it? And why that it’s happening? I Have a salt pool, so I don’t know what to do. Maybe the salt system is not producing enough chlorine? Please help !!!

    • Hi Laura-

      It can definitely be frustrating to experience these types of situations where it seems nothing is working. I’ve not personally used Bostik urethane grout before, but it seems there may be a couple issues here:

      1) Black discoloration (mold?). Not sure how long the tile and grout have been installed, but is it possible that the mortar underneath the tile is actually showing through the grout, giving the appearance of mold? You can measure the Free Chlorine in your pool to confirm whether your Saltwater Chlorine Generator is performing correctly. Even if FC levels are OK, it’s advised that you routinely shock the pool, which should kill any growth that’s in contact with the water. If you’re only seeing the black discoloration above the water line, it may be worth applying a small amount of bleach/baking soda mixture to an inconspicuous area –allow it to sit for 1/2 hour and then see if there’s any difference. This can help confirm whether it’s organic and at the surface level, or whether it’s inorganic or underneath the surface.

      2) Microbeads becoming dislodged. Scrubbing grout that is fully cured should not cause it to deteriorate. Otherwise, if the water chemistry has been severely outside normal levels for a long time, it’s possible it could affect the integrity of the grout. I’d recommend checking the balance (FC, pH, TA) to ensure your numbers are within spec just to eliminate this as a culprit.

      Ultimately, I would consider contacting Bostik customer support. Many of the grout products I’ve used in the past have great Technical Support teams that can help advise for unique situations such as this.

      Best of luck!


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