RV Water Tank Guide: The 3 Main Water Tanks

RV Water Tank Guide: The 3 Main Water Tanks

Posted by RVCampersUSA on Nov 2nd 2016

The 3 Main Water Tanks in Your RV: Everything You Need to Know

If you're new to RVing, you'll want to familiarize yourself with the 3 main RV water tanks pretty quickly. Get started here.

RVs have several different water tanks, each of which is intended for a specific purpose. Whether you're thinking of buying or renting an RV, it's important to familiarize yourself with these water tanks. Otherwise, you may end up creating a haven for bacteria and bad germs in the process.


When it comes to recreational vehicles (RVs), one of the most crucial systems to understand and maintain is the water tank system. The importance of water tanks in an RV cannot be overstated. These tanks provide the essential resource needed for cooking, cleaning, and personal hygiene while on the road.

In this article, we will take a closer look at the three main types of water tanks found in RVs, their functions, maintenance requirements, as well as some tips for prolonging their lifespan.

Understanding the Three Main Types of Water Tanks:

RVs typically have three main types of water tanks – the freshwater tank, the gray water tank, and the black water tank. Each of these tanks serves a specific purpose and requires careful handling and maintenance.

1. The Freshwater Tank: Its Functions and Maintenance:

The freshwater tank is responsible for storing and supplying clean water to your RV's faucets, shower, and toilet. It is important to regularly sanitize and maintain this tank to ensure the water remains clean and safe for use. Regularly flushing and cleaning the freshwater tank, as well as using a water filter at the point of entry, can help prevent contamination and maintain the quality of the water supply.

2. The Gray Water Tank: Handling and Disposal Considerations:

The gray water tank collects wastewater from sinks, showers, and laundry facilities. It is crucial to dispose of gray water responsibly to avoid contamination and environmental damage. Many RV parks and campgrounds have designated dump stations where you can safely dispose of your gray water. Additionally, using biodegradable soaps and minimizing the use of harsh chemicals can reduce the impact on the environment.

3. The Black Water Tank: Proper Use and Sanitation Guidelines:

Handling and maintaining the black water tank can be one of the less pleasant aspects of RV ownership, but it is essential for a clean and sanitary experience. The black water tank collects waste from the toilet and must be emptied regularly. Using RV-specific toilet paper and adding enzyme-based treatments can help break down the waste and control odors. It is also important to thoroughly flush and clean the tank after each use to prevent buildup and potential clogs.

What do I do if I think I have a clogged black water tank?

What if my RV water tank sensors aren't working right?

Tips for Maintaining and Prolonging the Lifespan of Your RV's Water Tanks:

To ensure the longevity of your RV's water tanks, there are some important maintenance tips to keep in mind:

1. Regularly inspect all tanks for leaks, cracks, or other damage.

2. Clean and sanitize the freshwater tank at least once a year.

3. Avoid overfilling the tanks to prevent damage or leaks.

4. Use proper RV-specific products for cleaning and treating the tanks.

5. Monitor tank sensors and gauges for accurate readings.

6. Insulate the tanks during colder weather to prevent freezing.

7. Use tank vent extensions to reduce odors during traveling.

How to Sanitize an RV Fresh Water Tank?

While bleach is the most common treatment to sanitize RV fresh water tanks, another alternative is to use the Happy Campers Extreme Cleaner product. We highly recommend the Extreme Cleaner as bleach can be very hard on RV water systems and components.

                Do NOT use bleach to treat gray and black holding tanks.

Maintaining a clean and sanitized fresh water tank is crucial for the health and safety of both you and your fellow travelers. By taking proper care of your RV's fresh water tank, you can ensure that the water you consume and use for various purposes remains pure and free from harmful bacteria or contaminants. In this article, we will guide you through the necessary steps to effectively sanitize your RV's fresh water tank, along with the appropriate chemicals to use and those to avoid.

Step 1: Preparation

Before you begin the sanitization process, ensure that your RV is parked in a well-ventilated area and that you have disconnected it from any external water source. Additionally, empty the tank of any remaining water and debris by opening all faucets and drains. It is important to start with a clean slate before sanitizing.

Step 2: Choose the Right Chemicals

When it comes to sanitizing an RV fresh water tank, using the appropriate chemicals is crucial. One of the most commonly recommended options is household bleach. However, it is essential to use unscented bleach that does not contain any additional additives, as these can potentially harm your fresh water system. We also recommend using a bleach alternative as bleach can be exceptionally hard on RV water systems and components. Alternatively, you can opt for specialized RV sanitizers available in the market, specifically formulated for this purpose.

Step 3: Determine the Correct Proportions

The next step involves determining the right amount of sanitizer to use. As a general rule of thumb, using approximately one-quarter cup of bleach or sanitizer per 15 gallons of water is recommended. However, it is always wise to refer to the manufacturer's instructions to confirm the exact proportions, as they may vary depending on the type of sanitizer you are using.

Step 4: Mixing the Sanitizer

With the correct proportions in mind, mix the chosen sanitizer with a sufficient amount of water in a clean container. Ensure that the sanitizer is thoroughly dissolved in the water before proceeding to the next step.

Step 5: Sanitizing the Fresh Water Tank

Once the sanitizer solution is ready, pour it into the fresh water tank through the filling port. To ensure uniform distribution, it is advisable to fill the tank at least three-quarters full. Next, close the filling port and turn on the water pump. Open all faucets, one at a time, until you smell the bleach or sanitizer solution, indicating that it has reached all the water lines and faucets.

Step 6: Let it Sit

After the solution has circulated through the entire system, allow it to sit for a minimum of four hours to effectively kill any lingering bacteria or contaminants. For optimal results, it is recommended to let it sit overnight. During this time, refrain from using any water systems that are connected to the fresh water tank.

Step 7: Flushing the System

After the required waiting period, drain the fresh water tank by opening all faucets and drains. Once empty, thoroughly rinse the tank and the entire system with fresh water until the smell of bleach or sanitizer is no longer present. This is crucial to remove any residual chemicals from the system.

Step 8: Final Checks

Lastly, conduct a final check by running fresh water through all faucets and drains to ensure that the system is now free from any sanitizer residue or contaminants. If necessary, repeat the rinsing process until the water appears and smells clean.

Chemicals to Avoid

While bleach and specialized RV sanitizers are safe and effective for sanitizing your fresh water tank, there are certain chemicals that should be avoided. These include household cleaners, detergents, and soaps. Using these substances can potentially damage the fresh water system and compromise the water quality.

Best Way to Maintain Your Black or Gray Water Tanks

To maintain clean and odor-free RV black and gray water tanks, it is crucial to utilize a reliable and effective tank treatment like Happy Campers. Here is a step-by-step guide on how to use Happy Campers holding tank treatment for superior tank maintenance:

1. Understand the tank capacity:

Before initiating the maintenance process, it is essential to know your RV holding tank's capacity. This information will help you determine the correct amount of Happy Campers treatment required for the tank. For example; one scoop (2 table spoons) treats up to 40 gallons.

2. Empty the tank: 

Start by emptying the RV holding tank completely. Ensure that all solid and liquid waste have been flushed out before proceeding to the next step.

3. Measure the appropriate amount: 

Refer to the Happy Campers instructions and guidelines to determine the correct amount of treatment needed for your specific tank size. Happy Campers offers measurement ratios based on tank capacity, ranging from 40-150 gallons.

4. Add treatment to the tank: 

5. Regularly empty and clean water tanks: 

To keep your holding tanks in perfect working order and odor free, just repeat that process each time you dump your black or gray water tank. 

By following these steps and incorporating Happy Campers holding tank treatment into your RV maintenance routine, you can prevent the buildup of waste, control odors, and ensure a clean and well-maintained tank for a more enjoyable camping experience. Remember to always follow the manufacturer's guidelines and recommendations for optimal results and consult a professional if you encounter any issues or concerns.

Conclusion: The Significance of Regular Maintenance for a Worry-Free RV Experience

Proper understanding and maintenance of the three main water tanks in your RV are crucial for a worry-free and enjoyable camping experience. By taking the time to learn about the functions and maintenance requirements of the freshwater tank, gray water tank, and black water tank, you can ensure a safe, clean, and efficient water system throughout your travels.

Remember to regularly inspect and clean your water tanks, handle and dispose of waste responsibly, and follow manufacturer guidelines for proper use. By implementing these practices and incorporating the tips mentioned in this article, you can prolong the lifespan of your RV's water tanks and enjoy a seamless water system wherever your adventures take you.