How To Clean Boat Water Tank? Without Removing It

Cleaning your boat’s water tank isn’t more complicated than cleaning anything else. You don’t have to be a professional or have special skills to do it.

The surprising thing is that a lot of boat owners still choose contractors to clean their boat water tank(s), which can cost up to many times the price of a DIY solution.

To help you get the task done let’s walk through a simple step-by-step boat water tank cleaning process.

knowing that boat water tanks come in different shapes, sizes, and places, some are reachable to remove or accessible inside to clean, and others are hard to get to.

But regardless of its reachability or accessibility, and what materials are the tank(s) made of. There is always a convenient way to get the job done.

To make the task easy I will present two methods: 

Cleaning the water tank without removing it. 
Removing and cleaning the water tank.

Let’s begin with Cleaning the water tank without removing it:

How To Clean Boat Water Tank Without Removing It.

Cleaning the water tank without removing it is not as difficult or complicated a process as some think. Let’s see how:

1. Remove all filter cartridges, aerators at all outlets.

2. Turn off the water heater from the electrical panel. (If installed)

3. Drain the tank completely through every faucet.

4. Fill half of the tank with hot water.
   
   A  temperature that does not cause any damage to the tank and water lines (check the manual). approx 50 Celsius – 122 Fahrenheit will be fine.

5. Shake the tank safely as possible.
   
   Take the boat for a short trip, about 30 minutes, to churn the hot water inside the system, which helps loosen the stickiness of sticky filth inside. Or try any appropriate way to shake the tank.

6. Drain the tank completely through every faucet.
   
   Drain it as fast as you can. Do it while the boat is moving if possible. To prevent any sediments from remaining inside.

7. Fill half the tank with water and an appropriate cleaner.
   
   Bleach damages aluminum tanks and has some environmental concerns. Read more about bleach in The Guardian
   
   If your choice is bleach Do Not Use More than (approx half an ounce ( 15 Ml ) of household bleach per gallon of water).

Bleach alternatives are a mix of lemon and vinegar ( approx 4OZ – 120Ml ) per gallon.
Or my favorite one the regular dish soap will be an effective and inexpensive solution.

8. Fill the entire system with a cleaning solution.
   
   Run the water from each faucet until you can see or smell the solution at each outlet.

9. Close and plug all faucets, outlets, and aerators. 
   
   Plug all aerators and the tank’s air breathers. Leave the system pressurized with the cleaning solution in it for 4 to 12 hours.

10. Drain the entire system and flush it thoroughly. 
    
    Flush it with potable water. Fill and drain at least 2 times, or until you are sure there is no cleaning solution left in the tanks.”

11. Clean and reinstall all aerators, and filter cartridges.
    
    Install new ones as appropriate. ( Recommended )

12. Fill the tanks with potable water. 

That’s How you clean a water tank on a boat without removing it.

Bleach in these concentrations ( Half an ounce - 15 Ml ) will not cause harm to most tanks. Other than aluminum tanks, which are not recommended for drinking water storage.

Now your waters are clean and potable. You may still smell or taste something strange for a while as a result of the cleaning solution or chlorination but it should not be strong or very noticeable, otherwise, you are fine. 

For additional protection, you can install Drinking-Water Filter & Purifier Systems. And keep in mind you have to clean the tanks once a year at least to keep the supply of potable water available.

As for the water tanks that you can remove, cleaning them is not complicated, just follow the following steps:

1. Remove any filter cartridges and any aerators at faucets and outlets.

1. Turn off the water heater (if installed) from the electrical panel.

1. Drain the tank completely through every faucet.

4. Remove all hoses and fittings connected to the tank. 

5. Remove the water tanks following the instructions manual.

6. Brush, scrape, and wipe the tank from the inside wherever your hand can reach. Use a stick and wrap a rag over the top for places far from your hand.

7. Install the tank in place and connect the lines.

7. Fill the entire system with a cleaning solution (approx. one ounce per gallon).

7. Run the water from each faucet until you can smell bleach at each outlet.

7. Close all the faucets and outlets and plug all aerators and the tank’s air breather, and leave the system pressurized with the solution in it for 2 to 6 hours.

11. Drain the entire system, and flush it thoroughly with potable water (fill and drain at least 2 times) until you are sure there is no residual solution left in the tanks. 

12. Clean and reinstall all the aerators and filter cartridges or install new ones as appropriate.

12. Fill the tanks with potable water. 

• Related Articles
  • How to clean a boat’s fuel tank
  • How To Clean Boat Holding Tank
  • How To Clean A Boat Engine Compartment

Boat Water Tank Cleaning Tips & Nots

• Algae, bacteria, and other contaminants can thrive in the entire water system, not just the tanks.

• Make sure there is no sediment left at the bottom, a yellowish layer on the inner walls, or any blackish green spots or dots anywhere you can see inside the tank

• If you removed the water tank(s) and cleaned it with your hands; no need to use more chemicals or keep them in the system longer.

• Bleach in these concentrations ( Half an ounce – 15 Ml ) and durations will not harm the tanks, plumbing, or pumps. And it will not require a lot of water to clear it out.

• Bleach causes damage to aluminum tanks and has some environmental concerns.

• Bleach causes damage to some types of watermakers. Read the instructions in the watermaker manual.

• The freshwater in your boat water tank will not always be fresh;

• During the cleaning process, it is noteworthy that repair and maintenance should be carried out if necessary.

Related Questions

How to know if the boat’s water tank is bad?

The boat water tank is bad if there are doubtless signs such as; odd water smell or taste or color, jammed pumps, clogged filters, visual inspection – sediments and dirt, or through water test. 

How often should a boat water tank be cleaned?

You should clean the boat’s water tank at least once every two years – annually would be better. Or after a longer storage time than usual. Or if there are signs that a cleaning procedure is needed. 

Final thought

Boat water tank problems can appear in several ways, the water tastes bad, looks dirty, has an unpleasant odor, water testing, or any combination of the four.

The freshwater in your boat water tank will not always be fresh; bad water source, bad filtrations, Leak into the tank, poor water circulation, rust flakes, paint chips, etc. 

Which will eventually lead to contamination of the water with bacteria, algae, or chemicals. 

That’s why it’s important to regularly clean out the tanks the right way, every time.

I hope this guide was helpful. Bookmark this page to remember and come back to it whenever you need it. Share this post to help someone else.