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If you aren’t familiar with RVs, the difference between black and grey water tanks may get confusing. You may not be sure what happens to the water in your RV after it goes down various drains. You may even wonder whether or not it is okay to pee in the shower of your camper.
In general, you should not pee in the RV shower. The water from the shower goes straight to your grey water tank, and urine should go to the black water tank.
However, sometimes urine ends up in the greywater tank. You know, like if you have kids showering in the RV. In this case, you will want to add in some extra cleaning steps to keep your grey water tank clean.
Grey Water Vs. Black Water in an RV
First off, let’s discuss the difference between black water and grey water tanks in an RV.
When you have fresh water holding tanks in your RV, or are hooked up to a water line in a campground, you have the ability to use that water by turning on your kitchen and/or bathroom sink, shower/tub, and flushing your toilet. When the water goes down the various drains, it winds up either in the black water or grey water holding tank.
The black water holding tank contains everything that gets flushed down your toilet, such as sewage.
Grey water in an RV is the used water from all sources other than your toilet – such as your kitchen sink, bathroom sink, and shower or tub drain. In addition, if your RV has appliances such as a dishwasher or washing machine, this water also ends up in the grey water tank.
Urine is not considered grey water; however, it sometimes winds up in the grey water tank.
For more information about RV holding tanks, see these resources:
- Where to Empty RV Black Water Tank
- 11 Pop-Up Camper Grey Water Ideas
- Does Your RV Smell Like Sewage? Here’s Why – And How to Fix It
What Happens When Urine Goes in the Grey Water Tank?
Urine can make your grey water tank smell.
Although grey water is thought of as the “cleaner” water tank, it can still smell bad due to hair, lint, soap residues, and sometimes urine that get into it.
You should keep your grey water tank clean and empty when possible. If you are at a full-hookup site, keep the grey water tank connected and valve open.
Otherwise, dump your tanks every 2-4 days at the campground dump station.
If you get urine in your RV’s grey water tank, you should empty and clean the holding tank out as soon as you can to prevent bad odors. Most grey water tanks do not have a flush system like the blackwater tank does. However, you can still clean the tank by adding dish soap and baking soda down the sink. Then fill the tank full before opening the line to flush it.
Where Can I Dump My RV’s Grey Water Tank?
As a rule, greywater should be dumped in the correct receptacle for disposing of grey and blackwater. This means you should dump your tanks at a dump station, into the sewer line or septic system.
On occasion, you will see some campgrounds have a separate grey water system that you can dump your greywater in.
If the campground does not have a dump station, many other places such as private RV parks, wastewater treatment plants, truck stops, and rest areas have dump stations.
If you have a cleanout that is accessible at your house you can dump the greywater there.
Pro Tip: Do not empty your grey water into a storm drain. Although grey water is less toxic than black water, it can still pollute water sources when dumped improperly.
Another place to dump your grey water is into a grassy area. Just make sure it is allowed to dump there first. Grass and plants act as filters for your grey water before it goes to the rivers and streams.
How Do I Stop My Grey Water Tank from Smelling?
To keep your grey water tank from smelling, make sure to keep as much dirt and food particles out of the line as possible. You need to clean your sinks and drains regularly and properly.
Since odors originate in sinks and drains, it is best to begin odor prevention at the source. Here’s a list of tips you can try.
- Keep grease out of the sink. Carefully wipe all dishes off with paper towels before washing. The grey water tank might emit a foul odor as a result of oil and grease buildup.
- Add a few drops of eucalyptus oil to the shower drain every time it smells. It has a pleasant scent and disinfectant characteristics that reduce the odors.
- For your bathroom and kitchen sinks, pour some orange soda in the drain and rinse with water.
- After emptying the grey water tank, put a few spoonfuls of baking soda into the sink. Then rinse down the drain with hot water.
- Use a mesh strainer to prevent bits of food from going down into your grey tank.
- After eating, scrape down your dirty plates into a trash can before washing. This will prevent food from entering or clogging your sink drain.
- Try the Geo Method – a mixture of water softener, laundry detergent, water, and bleach for cleaning the interior walls of the tanks.
- Try adding a deodorizer or freshener product to your drains, such as Elemonate, to reduce odors and leave your RV smelling fresh
How Do I Clean My RV Grey Water Tank?
Cleaning and maintaining your RV’s grey water tank is a relatively easy process. It entails using a cleaning agent, draining and rinsing the tank, and treating it on a regular basis. Following these steps proves to help a lot in reducing bad odor.
- Start by filling your RV’s grey water tank halfway with water then add your preferred cleaner; you can find good ones for affordable prices on Amazon. You can also use Dawn dish soap and baking soda.
- Drive to the nearest dumping station. The water will splash around the grey tank as the RV moves. This can be helpful in removing any buildup.
- Empty the tank into the dump facility. Simply attach one end of your sewer hose to the dump station hole and the other to your grey tank valve. Open the tank valve, and let it flow.
- Rinse the tank thoroughly by using a flush valve or a tank rinser.
- Add a treatment product – like this one from Amazon – that breaks down residue like grease and soap scum. This will help avoid clogs and odors in the tank.
Why Does My Grey Water Tank Still Smell Even after Cleaning?
If you have cleaned your RV’s grey water tank but it still stinks, then chances are there might be underlying problems in the valves or pipes, such as a crack or clog.
If the smell persists, check the following:
- Leaking valve – check all the valves for holes or openings that may be the source.
- Clogs – check your drains and pipes for clogging.
- Poor plumbing design – while this is hard to check, if the smell persists, it might be better to ask a professional to check your plumbing system.
Important Questions to Ask About Grey Water Tanks
If you still have other concerns about how to keep your grey water tanks in good working order, here are answers to some common questions:
How do I know when my grey water tank is full?
A holding tank sensor is standard on most RVs, and it will warn you when your tanks are about to fill up. Another indicator is that the water in your sink and shower drains is backing up. On certain smaller travel trailers, you may not notice until your drains stop draining.
Related reading: Why won’t my RV shower drain?
How accurate are the RV water tank sensors?
The accuracy of your tank monitors depends on how clean they are. Generally, if the RV holding tank sensors are reading incorrectly this is due to residue build-up. Use anti-grease detergent or an enzyme-based treatment to ensure this doesn’t happen.
My black water tank sensor is constantly reading 3/4 to 1/2 full – even after being dumped. However, the grey water tank sensor generally works better overall.
How often do I dump my grey water?
In general, you can expect to need to dump your grey water tank every 3-5 days. If you are boondocking and relying only on your freshwater holding tank, you can last up to 7-10 days with very careful water use.
How often you dump your grey water depends on how much water you use every day. It also depends on how many people are using water in your RV.
Some may dump often, some may not – especially if they are using outside sources like in a campground. The rule of the thumb is to always check the gauge of the tanks.
Can I use bleach to clean the grey tank?
You should not use bleach to clean your RV’s grey water tank as it will harm your RV’s seals and gaskets, as well as destroy beneficial bacteria that aid in waste breakdown.
However, I do add a cup of bleach to the freshwater holding tanks every couple of months. The city water has chlorine in it but you can sanitize the tanks better by adding a little bleach. However, you want to flush this water before using it.
Is it okay to leave the grey water tank open?
When you are at a campground with full hookups you should leave the grey water tank valves open. This will allow the water to drain continuously and you will not need to remember to open the valve and dump the tank.
If you are not hooked up to the sewer, leave the grey tank valve outside the RV closed. After flushing the black tank, flush the grey tank to clear any solids trapped in your sewer hose. You won’t have enough water to flush out the sewer hose if you leave this valve open.
Finals Thoughts on Whether Urine is Grey Water or Not.
Dealing with blackwater and grey water tanks can be confusing if you are new to RVing. Ensuring that you are properly taking care of your water holding tanks will help prolong their life.
Having said that, we all know that some people, especially kids, will pee in the shower. However, in an RV you need to take extra precautions when doing so.
When determining whether urine is grey water or black water, remember that anything coming out of a human body is considered black water. Though it may seem innocent enough, pee is not considered grey water and should not go down a shower drain. If it does, make sure you’re following the proper cleaning steps detailed above.
It’s not the end of the world if you pee in the shower, but getting urine in the grey water tank will increase the chance of your tank developing foul odors that could have been avoided.
If you found this guide helpful, you may want to check out our other resources about RV living/renting:
- 25 Expert Tips for Renting an RV for the First Time
- RV Rental Delivery and Setup at Your Campsite (Cost, FAQs, Examples)
- How to Rent an RV for an Epic Road Trip: Helpful Beginner’s Guide
- 15 Essential Tips for your First RV Family Camping Trip with a Toddler
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