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Capillary Wash Box
Capillary Wash Box

Restore sand to its original playing state and color by washing it

Eliminate sand replacements and reduce touch ups of your bunker sand by washing it instead

The Capillary Wash Box is an effective solution for washing algae, debris, silt, clay, and organic pollutants from bunker sand. By doing so, it preserves the sand’s percolation rate, color, and desired playing properties while eliminating the need for frequent sand touch ups and replacements.

The only bunker liner with possibility to wash the sand

Cutting sand costs by ⅔
Improving aesthetics
Restoring drainage & playability to optimal state




The Capillary Wash Box: part of our complete bunker protection system

Protect your investment in bunker sand by washing it instead of replacing it

Capillary Edge -
Maintaining design integrity

The Capillary Edge guarantees that the bunker’s shape remains true to its original design throughout its lifespan. This minimizes the need for crew intervention in edge trimming and eliminates the requirement for remodeling or reshaping bunker edges every decade.

Capillary Bunker Liner - Mastering drainage and moisture retention

Thanks to its proprietary Capillary Material, the Capillary Bunker Liner excels at swiftly draining excess water while simultaneously retaining the right amount of moisture. This ensures impeccable playing conditions in any weather and across all terrains, while also preventing the washouts and maintenance headaches typically associated with bunker upkeep.

How to wash your bunker sand in five easy steps

How the Wash Box works

The Wash Box and bunker sand washing relies on simple physics - smaller & lighter particles than sand will float in water whereas sand will sink to the bunker floor as it is heavier. By directing a water stream and washing the sand in its place, the particles will be separated and the contaminants can float to the surface and down the wash box, and enter the drain line.

How to wash your sand in five easy steps


Here is what some of our recent customers say about us and the Wash Box

Kinderlou Forest GC

Heath Allen

We used sand from an on-site quarry instead of shipping very expensive one to our location. We tested the sand, and found that its performance was marginal, but by using the Wash Box to remove fine particles, it became much more acceptable, and its performance was much better. Good quality bunker sand is expensive, so doing this obviously saved us  a lot of money, and those savings will continue for the lifespan of the bunker.

Hoover Country Club

LJ Robinson

The Wash Box is a huge deal for us. In the past, after a flood, we would skim our bunkers with flat shovels, but there was always some muck left over. With the Wash Box, we can skim, then connect a hose to the irrigation system and blast out the rest of the contamination. It will make a HUGE difference for us!

Castelconturbia GC

Giovanni Malcotti

When our contractor explained the benefits of the Wash Box to us, it was an easy decision to add it, one we took in an instant. It was a complete no brainer and we are happy with how it has helped us restore the sand colour without removing or adding any new sand!

Delsjö GK

Kevin Collins

Keeping our sands clean with the soils we have always has been a huge problem. Regardless of how good your construction is, you will always get contaminations in the sand here: clippings, algae, clay and silt run-offs and the like. This is the first solution we have ever seen work where we do not have to replace the sand. I'm stunned by the results and also all the money we save on sand!

The Breakers Palm Beach

Mark Reid

I am a big fan of the Wash Box. To have the ability to remove fines and algae, and bring sand back to its original pure-white state is amazing. I’m never worried about bunker consistency now!

The bunker liner system with the best ROI

By eliminating frequent sand touch ups and replacements, you will be able to cut sand costs with ⅔ of your bunkers’ operating budget

Curious what the calculation looks like? Download our flyer or contact us for a custom calculation for your golf course!

Why should you wash your bunker sand?

Eliminate sand touch ups and replacements

By washing the sand instead of topping it up with new or replacing, it can be restored to its original moisture holding and drainage properties.

Eliminate wet bunker bases

By removing particles finer than sand, such as silt, clay and fines that hold moisture, the bunker bases won’t hold too much moisture any longer.

Preserve the sand’s percolation rate

Did you know new bunker sand drains with a rate of 22’ per hour when it’s brand new, and 8’ after just two years? Using the Wash Box is a way to restore this rate.

Maintain desired sand color

Contaminated sand is not a good sight for the eye. By washing it you can restore it to its original color. 

Achieve desired playing properties

When sand is contaminated and holds too much moisture it’s usually becoming denser for players.

Technology overview and installation process

The Capillary Wash Box is easy to install and is fitted at the same time as the liner. It should take no more than 20 minutes to do. It is installed in a vault in the lowest part of the bunker together with bunker sand surrounding it


Out of the box


Less than
10 minutes per bunker

Washing time

1-2 hours per bunker
depending on bunker size

Washing frequency

When bunkers drain poorly, sand is too dense or visual contamination is present. Recommended at a minimum every 3 years

Sand replacement rate

None as it can be washed to its original properties to maintain desired playability & characteristics

bunker edge capillary

step 1

Preparative ground work

We provide instructions or help you with preparing the ground by emptying the bunker, verifying or reconstructing drainage and excavating the Wash Box vault from gravel.

bunker edge capillary

step 2

Vault preparations

A 2 × 2 feet wooden frame is placed where the wash box will be installed to protect the vault from bunker liner infringement once the liner is installed. A fabric liner is installed on the short sides of the vault, with the drainage pipe penetrating it.

bunker edge capillary

step 3

Wash Box installation

The Wash Box is installed in the vault, on top of the drainage pipe. To allow washed water to enter the drainage, a hole is cut in the drainage pipe where the wash box is fitted. Sand is filled up around the Wash Box.

bunker edge capillary

step 4

Bunker liner installation and sand fill

The bunker liner is installed and the bunker is filled with sand.

bunker edge capillary

step 5

Enjoy your installation of Capillary with 15 year performance guarantee and full product support

Once the installation is done, we are proud to be the only industry supplier to offer a full 15 year performance guarantee for our Capillary Material and Wash Box.

Frequently asked questions about the Wash Box, Capillary Bunkers and our bunker liner

 See all FAQs
What are the benefits of installing a wash box in my bunker and will it pay for itself?

The Wash Box is useful for several reasons. First, it gives you access to your drain line at a later date if you ever need it. Second, it is installed within the vault and helps create a deeper sand profile to help manage the water release curve. Last, and most importantly, it enables you to clean your sand and remove any debris or contamination without having to replace it, which is time-consuming and expensive. So, a Wash Box pays for itself very quickly when taking sand costs into account.

How long does it take to clean a bunker with the Wash Box?

It depends on the bunker size. An average bunker usually takes no more than two hours to clean.

Where should I place my Wash Box?

The Wash Box is placed in a vault over the low point in the bunker. It sits on the drain pipe and the vault is filled with bunker sand.

Will I lose sand in the drainage when washing?

No, if you wash carefully the sand will stay in the bunker and only light particles such as sod, silt and organic matter will go down with the water into the drain pipe.

Can you install the Wash Box in an existing bunker?

Yes you can if it is a Capillary Bunker. Find the drainpipe, make a 2x4 feet opening with a diamond saw. Pull out the drain gravel, place the Wash Box on the drain pipe, fill the new vault with bunker sand to the top.

Can the Wash Box be installed with other bunker liners?

No. The reason for that is simple: No other bunker liner in the market can withstand the high pressure water beam without either displacing too much sand, ripping the bunker liner or damaging it in other ways. The Capillary Material with its superior durability can easily withstand the pressure the water beam creates and wash the sand in its place.

Can the Wash Box be installed with other bunker liners?

No. The reason for that is simple: No other bunker liner in the market can withstand the high pressure water beam without either displacing too much sand, ripping the bunker liner or damaging it in other ways. The Capillary Material with its superior durability can easily withstand the pressure the water beam creates and wash the sand in its place.

Can any bunker sand be used with a Wash Box?

Yes, any bunker sand can be used with the system, and any sand can be cleaned with the unique and patented system.

How much does the Wash Box cost and how long does it take to install?

The Wash Box is included in your quote for the bunker liner for all installations. If you have prepared the space/vault for the Wash Box when preparing your bunker for liner installation, it will take no more extra than 20 minutes to install Wash Boxes in a bunker. 

How many Wash Boxes do I need per bunker?

It depends on the size of your golf bunker. Usually one per bunker is enough. Otherwise we generally recommend one every 20 feet if you have a larger sized bunker. Generally, the smaller particles (contaminants) will only float for about 30 seconds. If there is too large of a distance between the wash boxes there is a slight risk the contaminants will sink back in the sand on their way to the drain line. You want to prevent that.

We would love to help you with your bunker renovation project

Contact us and one of our experts will reach out to you as soon as possible.

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