Choosing the right tank size for your pressure washing setup is one of the most important decisions you’ll make when getting your equipment ready for action. Whether you're a professional tackling large commercial projects or a homeowner sprucing up your driveway, selecting the right size tank will impact both your efficiency and overall performance.

So, how do you figure out which tank size is best for your needs? It’s not just about choosing the biggest tank—there are several factors to consider before making your decision. Here’s a breakdown of the key elements to help guide your choice.

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1. Type of Jobs You’ll Be Doing

The first consideration is the types of projects you'll be working on. Different cleaning tasks require varying amounts of water, and knowing what you’re likely to tackle most often can help you choose the appropriate tank size. See all of our available tank options here.

• Residential Jobs: For smaller projects like cleaning driveways, decks, or patios, you’ll likely need a tank that can handle a few hours of work without constant refilling.
• Commercial Jobs: Larger areas, such as parking lots, building exteriors, or heavy-duty cleaning, require more water for longer periods.
• Softwashing: Softwash systems often use large volumes of water and cleaning solution, so if you're primarily softwashing, you’ll need more liquid capacity for those extended applications, especially if using an 11gpm unit like a Comet P40 or AR45.
• Heavy Duty Cleaning: Jobs like graffiti removal or oil stain cleaning can demand more solution, so they might require larger tanks as well. In addition, these types of jobs often have little to no access to a spigot.

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2. Pressure Washer Flow Rate (Gallons Per Minute - GPM)

Your pressure washer’s flow rate plays a critical role in determining how much water you’ll use per minute, and therefore how large a tank you’ll need.

• Higher GPM: Pressure washers with higher flow rates (5-8 GPM) will use more water per minute, so you’ll need a larger tank to keep the system running without needing to refill too often.
• Lower GPM: For systems with lower GPM (2-4 GPM), you can typically work with a smaller tank. These systems use less water, allowing for more flexibility with tank size.

To estimate the amount of water you'll need, simply multiply the GPM by how long you plan to run the system. For instance, a 5 GPM system will use 300 gallons of water in 60 minutes.

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3. Job Duration

How long do you typically work before needing to stop for a refill? Larger tanks can allow you to work for longer periods without interruptions. If you’re tackling large jobs like cleaning entire buildings, you might want a bigger tank to keep the job running smoothly without wasting time.

• Shorter Jobs: If your jobs are usually shorter, you can get by with a smaller tank that still offers enough water to finish the task.
• Longer Jobs: For extended projects, a larger tank will allow you to keep working continuously, without needing to find a water source mid-project.

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4. Portability vs. Volume

If you're planning to move your setup around frequently, portability will be a key factor. Larger tanks provide more capacity but can be heavier and more difficult to transport. On the other hand, smaller tanks are lighter and easier to move, but they may require more frequent refills on larger jobs.

• Smaller Tanks: Easier to maneuver and store but may require more time spent refilling, especially for large-scale projects.
• Larger Tanks: Ideal for big jobs, but heavier and bulkier. If your setup will be stationary for most projects, a larger tank may be beneficial.

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5. Water Source Accessibility

Do you have easy access to a water source on-site, or will you need to bring your own water? If your work takes you to locations where water access is limited, a larger tank may be necessary. However, if you're working in areas with easy access to spigots, you can generally get by with a smaller tank and refill as needed.

• No On-Site Water: If you’ll be working in areas without nearby water, you’ll need a tank that holds enough to get you through the job without needing to leave the site.
• Easy Water Access: If you’re working in places where it’s easy to access a spigot, you can work with a smaller tank and refill more frequently.

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6. Weight Considerations (Trailer and Vehicle Restrictions)

When choosing a tank, it’s essential to consider the weight of both the tank and the water it holds, especially if you're mounting the tank on a trailer or truck. Water weighs approximately 8.34 pounds per gallon, so a tank's weight can add up quickly. For example:

• A 100-gallon tank filled with water weighs about 834 pounds.
• A 200-gallon tank filled with water weighs about 1,668 pounds.
• A 500-gallon tank filled with water weighs about 4,170 pounds.

Important Factors:

• Vehicle Weight Limits: Be sure that your trailer or truck can handle the weight of the tank and water, along with the weight of your other equipment. Overloading a vehicle can be dangerous and can damage both your tank and your vehicle.
• Trailer/Truck Balance: You should also consider how the tank’s weight will affect the balance of your vehicle or trailer. An overly heavy tank on the back of a truck or trailer could affect driving stability, braking, and safety.

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7. Budget

Your budget will likely be a major factor in your decision. While larger tanks may offer more capacity, they are generally more expensive, both in terms of the tank itself and the additional weight it brings (which may require more robust trailers or trucks).

• Smaller Tanks: More affordable, lighter, and easier to store and transport. However, they may not be as effective for long jobs or large-scale cleaning tasks.
• Larger Tanks: Cost more but provide more capacity for longer jobs and greater efficiency. If you plan on doing larger commercial projects, the investment in a larger tank will pay off over time.

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Graph: Gallons of Water vs. Duration of Use

Here’s a helpful visual that shows how long a tank will last based on the Gallons Per Minute (GPM) of your pressure washer, for both situations: when you’re filling from a spigot and when you're relying entirely on the tank's water supply.

Assumptions:

• Water Flow Rate (GPM): We’ll assume you're using a system with either 3 GPM, 5 GPM, or 8 GPM.
• Filling from Spigot: The time it will take for the tank to be depleted if you’re filling as you go.
• Without Filling: The time it will last if you’re not refilling during the job.

GPM	50 Gallons	100 Gallons	200 Gallons	300 Gallons	500 Gallons
3 GPM	16.7 mins	33.3 mins	66.7 mins	100 mins	166.7 mins
5 GPM	10 mins	20 mins	40 mins	60 mins	100 mins
8 GPM	6.25 mins	12.5 mins	25 mins	37.5 mins	62.5 mins

This graph will give you an idea of how long your tank will last depending on your system's GPM rate and whether you're refilling from a spigot or relying solely on the water in the tank.

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Conclusion

Choosing the right tank size for your pressure washing setup is all about understanding your specific needs and considering factors such as job type, flow rate, duration of use, and accessibility to water. Pay attention to the weight limitations of your trailer or vehicle, and factor in portability, tank material, and your budget to make the most informed decision.

At Livingston Spray Company, we’re happy to help you find the perfect tank for your pressure washing system. Contact us today for expert advice and a selection of high-quality tanks that fit your needs!