Can you put bleach in an RV black water tank?

In this blog post, we will answer the following question: Can you put bleach in an RV black water tank? We will explain how to drain, clean and disinfect the RV black water tank.

Can you put bleach in an RV black water tank?

Yes, it is allowed to put bleach in an RV black water tank. You can make a mixture of one-quarter cup of bleach with one gallon of water and clean the waste tank. 

Another effective method is to add a bag of ice cubes to the toilet with a little water and take your RV around the neighbourhood. For this to be effective, you have to take many turns so that the ice moves vigorously in the tank and cleans the probes. Another method is to introduce a garden hose to the toilet with a 90-degree elbow and rinse well.

What is a black water tank and how to clean it?

The black water from your van is stored in a removable cassette outside your vehicle. This black wastewater must be emptied into tanks provided for this purpose. To do this, you must open the exterior door of the vehicle and remove the cassette using the handle. Open the cap and pour the contents of the tank into an escape hatch.

Once you have emptied the black water tank, you can rinse and clean it. To clean the cassette, pour at least 2L of clean water inside and add a disinfectant and deodorant such as bleach tablets.

You can leave or replace the cassette in the van and hit the road. The movement of the vehicle on the road will allow the water to thoroughly clean the black water tank. It is also important to clean the toilets of your van.

For many, the black water tank is the more important of the two to maintain. No one likes the smell of fermenting human droppings. In addition, if you do not see its maintenance, the detector will quickly tell you that the tank is full when it is not.

Blackwater tank maintenance products are sold in several forms: liquid, powder or prepackaged capsules. The product is usually diluted with water and poured into the toilet when the tank is clean and empty.

It should be noted, however, that not all products have the same effect on the tank: some products only mask odours, while others neutralize the decomposition of droppings and dissolve them. To keep the walls of your tank in good condition, we recommend that you use the second option instead.

How frequently should you clean the RV’s wastewater tanks?

The grey water tank must be completely cleaned at least once or twice a year. When used, bad smells can appear and spread in the motorhome. If you spend a lot of time in your van you will do this cleaning several times a year.

The black water tank can be cleaned more frequently than the grey water tank depending on your use. If you live year round in your RV, you can clean your wastewater tanks once a month.

How to empty the RV’s black water tank

Your water tank should have a drainage system, which will not consist of much more than a tap located at the lowest point of the tank. If access to this tap is not comfortable for you, you should consider placing a pipe and its corresponding tap, in a more accessible place.

If you have to modify your system, take the opportunity to make sure that the drain outlet is placed in the lowest part of the tank and that it allows the complete evacuation of the water contained in it. The bottom of the tank is a better location than a wall.

Freshwater tanks do not usually have slopes that facilitate their emptying, such as faecal or grey water tanks. The bottom is usually flat since the water is extracted by aspiration, through a tube that enters the tank from the top.

Remember that even if you have a simple method to empty the tank, introducing clearly dangerous water, no matter how good a filtration system you have, is a mistake. Above all, it is important to stay away from chemical contamination: pesticides, etc.

As you have read, disinfection, water treatment, filtration, etc. .. are methods aimed at ensuring a trip without health problems. All in all, in my opinion, while travelling in the South of the country in the summer season, you should chlorinate your water tank once a month.

One more tip, if you don’t use your caravan, keep the tanks (not just the drinking water one) empty and dry if possible. Not all tank drainage systems allow their complete emptying, many leave sediment at the bottom, which is still a design problem in my opinion, which should be solved if possible.

How to disinfect the RV black water tank?

Once the water tank is clean it can be disinfected. Note that disinfection does not “clean” the tank, it only kills the bacteria that after all cling to the pipes or the tank.

If the tank has water, the first thing is to empty it, use the tank drain valve, which has its intake in the deepest part of your tank.

The idea is to fill the freshwater tank with a 5% sodium hypochlorite solution, about 1 litre of solution for every 12 litres of fresh water. Chlorine should not be poured directly into the tank, prepare the solution outside and then fill your tank.

This mixture puts a 50 ppm (parts per million) concentration of chlorine in your water system, which will quickly kill harmful bacteria, viruses, and slime-forming organisms that may be living in your motorhome. A higher concentration of chlorine can damage the tank, pipes and other items, so you must be careful when measuring.

Open all the water outlets, one by one, allowing the chlorine solution to pass through all the circuits recorded in your installation.

Turn off the taps a couple of minutes after you can smell the chlorine in the water coming out of the tap.

The bottom line

Besides knowing that it is safe to put bleach in an RV black water tank, remember that the tanks or cassettes that collect the sewage have a rotating tube through which they are discharged into the corresponding drain, and which must be connected to a septic tank or the sewer. For cleaning, it is advisable to have a running water tap nearby, different from the clean water tap.

Please let us know if you have any comments or questions on the content.

FAQ on Can you put bleach in an RV black water tank?

What is the procedure to treat sewage?

Wastewater treatment begins with the physical separation of large solids (garbage) from their current, using a system of grids (meshes), although such wastes can also be crushed by special equipment; subsequently a grit is applied (separation of solids

How to clean the clean water tank of an RV?

To clean the clean water tank of an RV, follow this guideline: to each litre of water, you must add 2 drops of 5% chlorine. If you do, your water will be much more drinkable and clean, eliminating the risk of acquiring different diseases. At we have many years of experience renting and improving your caravan

Where to dump the sewage?

The sewage is poured directly into an aseptic tank or cassette. The tanks or cassettes that collect the sewage have a rotating tube through which they are discharged into the corresponding drain, and which must be connected to an aseptic pit or the sewer

Where does the grey water come from? 

Gray waters are all those waters that are collected from the bathrooms of the buildings, except for the waters of the toilet. They are collected from the bathtubs, showers or sinks of any building that contains these elements.


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