How to Clean a Boat Fuel Tank?

Last Updated on October 1, 2022

Boat fuel tanks can get dirty over time and need to be cleaned in order to run properly. learn how to clean a boat fuel tank in this article.  

Boat owners know that a well-maintained vessel is key to having a great time out on the water. One important aspect of boat maintenance is keeping the fuel tank clean.  

There are a few ways to clean a boat’s fuel tank. One is to use a commercially available tank cleaning product that you can buy at an auto parts store.  Over time, sediment and algae can build up in the tank, which can cause problems with your engine. 

In this article, we will show you how to clean your boat’s fuel tank using simple methods that are safe for both you and your boat. So, whether your fuel tank is full of dirt and grime or just needs a good general cleaning, follow these steps and get it done quickly and easily!

DIY How To Clean Your Gas/Fuel Tank In Your Boat

  • Remove the fuel tank from the boat. This will require some disassembly of the boat, so refer to your owner’s manual for specific instructions.
  • Place the fuel tank on a flat surface and inspect it for any damage or leaks. If there are any damaged areas, they will need to be repaired before proceeding.
  • Clean the outside of the fuel tank with a mild soap and water solution to remove any dirt or grime build-up. Rinse the tank thoroughly with clean water and allow it to dry completely before proceeding.
  • Pour a small amount of fresh gasoline into the tank and swish it around to loosen any stubborn residue that may be clinging to the sides or bottom of the tank.
  • Drain the gasoline out of the tank and dispose of it properly according to local regulations (do not pour it down a drain!).
  • Fill the tank with fresh water and add a marine-grade holding tank cleaning solution according to the manufacturer’s directions. Allow this solution to soak in the tank for at least 12 hours before draining it out completely.

How to Clean Boat Gas Tank Without Removing?

If you’ve ever dealt with a boat gas tank that’s gone bad, you know it’s a big pain to have to remove the entire tank just to clean it out. Luckily, there’s an easier way! With a little elbow grease and the right supplies, you can clean your boat’s gas tank without removing it from the boat.

Here’s what you’ll need: 

  • Safety goggles 
  • Rubber gloves
  • A bucket 
  • Marine grade cleaners (we recommend Bilge Kleen) 
  • A garden hose 

There are several ways you can clean it without taking it out of the boat. One way is to add a cleaning solution to the gas tank and then run the engine until the solution has been circulated throughout the system. 

Another way is to pump out some of the gas and then use a hose to flush out the tank with fresh water. Whichever method you choose, it’s important to make sure that the boat’s gas tank is completely dry before you add fresh fuel. By taking these simple steps, you can keep your boat running smoothly and prevent costly repairs down the road.

How to Clean an Aluminum Boat Gas Tank?

If you own an aluminum boat, chances are you’ll need to clean your gas tank at some point. Whether it’s due to normal wear and tear or because you’re switching out old gas for new, it’s important to know how to properly clean your tank. 

Here are some tips on how to clean an aluminum boat gas tank:

1. Start by draining all of the gas from the tank. This can be done by siphoning it out or by opening up the drain plug at the bottom of the tank. Once all of the gas is out, rinse the inside of the tank with fresh water.

2. Next, mix up a solution of 1 part household bleach and 10 parts water in a large bucket or container. Carefully pour this solution into the gas tank and let it sit for at least 30 minutes. 

3. After 30 minutes, flush out the bleach solution with fresh water again. You may need to do this a few times until all traces of bleach are gone from the tank. 

4. Finally, dry out the inside of the tank completely before adding new fuel. A good way to do this is to put a couple of inches of sand in the bottom of the tank and then turn on a hair dryer and aim it into the tank (make sure not to overheat any areas).

Letting air circulate like this will help evaporate any remaining moisture inside the tank.

Cost to Clean Boat Fuel Tank

According to, the cost to clean a boat’s fuel tank can range from $100 to $1,000, depending on the size and type of boat. The average cost is around $500. 

For example, a 20-foot boat with a gas engine would require about five gallons of fuel, which would cost about $25 to fill up.

The Boat US Foundation estimates that it costs about $0.50 per gallon to have a professional clean a boat’s fuel tank.

How to Clean Plastic Boat Gas Tank?

Whether your boat is for business or pleasure, keeping your gas tank clean is essential to the performance of your vessel. Plastic boat gas tanks are especially susceptible to build-up and contamination, so it’s important to clean them regularly. 

Here’s a step-by-step guide on how to clean a plastic boat gas tank:

Step 1: Start by draining all the fuel from the tank. This can be done by running the engine until it runs out of gas, or by siphoning the fuel out with a hose. 

Step 2: Once the fuel is drained, add a gallon of fresh water to the tank and swish it around to loosen any dirt or debris that may be clinging to the sides.

Step 3: Drain the water from the tank and rinse it out several times with fresh water until all traces of dirt and debris are gone. 

Step 4: To remove any lingering contaminants, fill the tank with a mixture of one part bleach to ten parts water and let it sit for 24 hours before draining it again thoroughly. 

Step 5: Finally, rinse out the tank several more times with fresh water until all traces of bleach have been removed and allow it to dry completely before adding new fuel.

Boat Fuel Tank Vacuum

A boat fuel tank vacuum is a process of removing all the air from the tank in order to fill it with fuel. This is done by using a pump to create a vacuum inside the tank, which sucks out the air. 

Once all the air is removed, the tank can be filled with fuel without any danger of explosion. The main reason for doing this is to prevent fires onboard boats. Fuel tanks that are not properly vented can build up pressure and heat, which can lead to an explosion if there is a spark or flame present. 

By removing all the air from the tank, you eliminate this risk. It’s important to note that you should never use a household vacuum cleaner for this purpose, as they are not designed for vacuuming flammable liquids like gasoline. 

Instead, you should use a dedicated boat fuel tank vacuum pump, which can be purchased at most marine supply stores.

How Do You Clean a Dirty Boat Gas Tank?

Over time, your boat’s gas tank can become filled with sediment and debris. This can clog up your fuel lines and prevent your engine from running smoothly. Fortunately, there are a few simple steps you can take to clean out your dirty gas tank. 

First, make sure that the tank is completely empty. 

Next, fill the tank with a solution of water and marine-friendly soap. Then, using a long-handled brush, scrub the inside of the tank to remove any build-up. 

Finally, rinse the tank thoroughly with clean water. By following these steps, you can keep your boat’s gas tank clean and ensure that your engine will run smoothly all season long.

How Do You Remove Debris from a Boat Gas Tank?

If you’ve ever had to deal with a clogged gas tank, you know it can be a real pain. Here’s a step-by-step guide on how to remove debris from a boat gas tank: 

Step 1: Start by draining the fuel from the tank. You can do this by disconnecting the fuel line and running it into a container. 

Step 2: Once the fuel is out, take off the gas cap and inspect the inside of the tank for any debris. If there is any, use a small brush or other tools to remove it.

Step 3: Now that the tank is clear of debris, you’ll need to flush it out with some fresh gasoline. This will help remove any residue left behind from the debris. 

Step 4: Finally, put everything back together and fill up your tank with fresh gasoline before heading out on your next adventure!

How Do You Remove Algae from a Boat Gas Tank?

If you’ve noticed algae growing in your boat’s gas tank, it’s important to remove it as soon as possible. Algae can clog fuel lines and filters, and prevent the engine from running properly. 

To remove algae from a boat gas tank, start by draining the tank completely.

Next, clean the inside of the tank with a brush or rag to remove any loose algae. 

Then, fill the tank with a mixture of fresh water and vinegar, and let it soak for several hours. 

Finally, drain the vinegar solution and rinse the tank thoroughly with fresh water.

What Can I Use to Clean My Fuel Tank?

If you’re wondering what you can use to clean your fuel tank, the good news is that there are a few different options. The first option is to use a commercial fuel system cleaner. This type of cleaner will help to remove any build-up or deposits that may be in your fuel tank.

Another option is to use a homemade solution of vinegar and water. This mix can also help to break down any deposits or buildup in your tank. Finally, you can also have your tank professionally cleaned by a mechanic.


The best way to clean a boat fuel tank is by using a pump and hose to remove the majority of the fuel.  After the majority of the fuel has been removed, use a rag or sponge to wipe away any residue. 

If there is still some residue left in the tank, use a brush dipped in gasoline to scrub it away. Be sure to wear gloves and goggles when cleaning your boat’s fuel tank.