There are tons of positives to RVing. You get to see the country, meet new people, have the freedom to go when and where you want. But then there are some parts of RVing that no one likes to talk about. One of those is dealing with the black tank. It is a dreaded but inevitable task of RV life. Or it used to be! But that was before RV composting toilets became more widely available.
If you hate dealing with – or being limited by – the black tank, you’re going to want to keep reading.
Table of Contents
- What Is a Composting Toilet?
- How Does an RV Composting Toilet Work?
- Advantages of Using a Composting Toilet in Your RV
- Disadvantages of RV Composting Toilets
- Who Is A Composting Toilet For?
- Enjoy Extensive Off-Grid RVing With a Composting Toilet
What Is a Composting Toilet?
An RV composting toilet is a great alternative to a traditional RV toilet and is frequently used on boats and in off-grid cabins as well. In short, a composting toilet composts waste rather than flushing it with water and plumbing. The result of composting is waste turns into soil/fertilizer, and you can simply toss it out in the trash or a compost pile.
Using a composting toilet in an RV means no more dumping the dreaded black tank. It also means that the previous limitations of your black tank capacity – especially when it comes to off-grid RVing or boondocking – no longer apply.
How Does an RV Composting Toilet Work?
A composting toilet works with absolutely no water. It is designed to separate liquids and solids and send each to its own small tank or bucket. This is key because when liquid and solid waste mix, sewage is created. By keeping them separate, the solid waste is allowed to be decomposed by bacteria and enzymes in a natural composting manner.
The solid waste bucket is filled with dry peat moss or coco coir compost starter that looks like dirt. This organic material dries out the solid waste and aids in decomposing. Eventually, your solid waste becomes compost. Most composting toilet models have a crank that can turn the compost and keep it well mixed.
The liquid waste or urine is captured in either a separate bucket or plumbed into a larger holding tank to be dumped at a dump station. The bucket option is removable so it can be dumped in an appropriate place outside or into a sewer receptacle.
Used toilet paper can be but is usually not places in the solids bucket, as it takes up space. Instead, it is placed in a trash can to be thrown out separately.
Do Composting Toilets Smell?
Generally speaking, no. Not like a black tank anyway. Let us explain:
Composting toilets do not smell as bad for two primary reasons. First, because there is no liquid mixed with the solid waste, it doesn’t turn into sewage and give off that odor all RVers dread. The smell of the solid waste in the bucket isn’t pleasant – like a manure smell – but not nearly as strong and pungent as black water. Also, the only time you smell it is because of reason #2.
Reason #2 is that there is a small 12V electric fan attached to a vent hose that pulls the air out of the solid waste bucket and to the outside. The fan keeps any smell from rising up and out of the bucket into the RV. The only time you whiff the solid waste manure smell is when you are changing the compost.
Dealing With the Liquid Waste
The only “bad” smelling part of the toilet is dealing with the urine bucket. As mentioned, the urine is typically either captured in a bucket or jug. This bucket needs to be emptied when filled into a traditional toilet or in an appropriate spot on the ground after diluting.
One way to avoid having to use buckets is to plumb a line from your composting toilet into an RV “yellow” tank to allow for more capacity. You would then need to dump this tank at a typical dump station.
Dealing With the Solid Waste
Usually, filling your RV compost bin takes a few weeks. Once it is full, the bucket is removable, so you can do the dirty work outside. Just dump the bucket into a trash bag (preferably also compostable) and toss it out.
Solid waste may be dumped and composted outside if done so properly on your own property (or you have permission). The compost created from human waste must not be used on any plants that will be consumed by humans. Please research proper handling instructions of solid waste compost before dumping.
Advantages of Using a Composting Toilet in Your RV
There are lots of benefits to upgrading your RV toilet to a composting toilet. Here are a few:
Great for Boondocking Off-Grid
First and foremost, it is an excellent choice for boondocking or RVing without hookups. This is because an RV composting toilet 1) doesn’t use any freshwater, 2) it doesn’t use or require a black tank, and 3) it uses minimal electricity. All perfect for off-grid living!
Not only do you not have to worry about filling your black tank, but you also use so much less fresh water than with a standard toilet. This means your fresh water tank will last you longer as well. It’s a win-win!
Opportunity to Combine Black & Grey Tank Capacities
Adding a composting toilet means you’ll have no use for your black tank. If you’re lucky enough to have your grey and black tanks installed at the same level, you can actually combine these tanks to make your grey water capacity even larger!
To do this, you will need to add a gate valve that you connect to the outlet pipe. You then pull your other valves so your grey water can flow into your now unused black tank.
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PS: If your RV is like ours and you can’t combine your tanks, you can always rip out your black tank and use the space for something else, like 8 Battle Born Lithium-Ion Batteries like we did! 😉
Great for RVs With Small Tanks
Because of the first two reasons stated above, the composting toilet is really amazing for RVs with smaller tank capacities. Suddenly, an RV with small freshwater, grey, and black tanks will be able to extend their freshwater and increase their grey water capacity. This means they will be able to majorly extend their off-grid boondocking stretches and go longer in between dump station visits.
Never Dump Your Black Tank Again
While you still need to deal with your waste, it won’t be as frequent or nearly as smelly. You’re also not in danger of an awful sewage accident at the dump station! While everyone has their own opinion, we think that dealing with the composting toilet is much more preferable than dumping a black tank or a cassette toilet.
Save Water & Be Eco-Friendly
Since using our composting toilet, we’ve become extremely aware of the amount of water used in ever flush of a residential toilet. If you’re environmentally conscious, you’ll definitely feel the satisfaction of doing your part to save water and be eco-friendly!
Disadvantages of RV Composting Toilets
Although we love and highly recommend our composting toilet, we’d be remiss if we didn’t also share the few disadvantages. We understand that an RV composting toilet isn’t for everyone. And if you’re hooked up to water and sewer all the time, the water-saving advantages listed above might not be as valuable to you.
First, RV composting toilets are more expensive than a regular RV toilet. Second, it would require an installation as few RVs come with composting toilets already installed. Additionally, some composting toilets have strange shapes and sizes that might not work with the layout of your RV bathroom.
You’ll also need to think about where the vent is going to run to. Pro Tip: try not to vent to the door-side wall of your RV.
Another disadvantage of an RV composting toilet, and by far the biggest one, is that you need to empty liquids almost daily for most models. Although this varies depending on use, having a daily chore associated with the toilet is a drag. We recommend getting either a second urine bucket to swap in when the other is full or looking into plumbing-in a “yellow” tank.
It also takes a bit to get used to using and emptying an RV composting toilet. There is a learning curve, but if you figured out how to dump your tanks, we know you can figure this out too.
Who Is A Composting Toilet For?
Now, just like most features of RVs, the composting toilet isn’t going to be for everyone. As a traveling couple who loves boondocking, this was an awesome upgrade. If you’re preference is to stay in RV parks with full hookups, the convenience of attaching your sewer and not dumping a liquid bucket every day might very well win out.
RV families with more than 2 people might also find that changing the liquids and the solids portions have to happen much more frequently. Monitoring the bucket levels, while easily done with a glance, might induce some anxiety if you’re having to take care of liquids multiple times per day.
Enjoy Extensive Off-Grid RVing With a Composting Toilet
Upgrading to an RV composting toilet is an easy choice if you love boondocking and/or really hate dumping your black tank! It is a simple way to take one of the worst parts of RVing and make it much less painful (and smelly).
We personally installed an Air-Head Composting toilet in 2018 for full-time RV use and haven’t looked back. That upgrade took our boondocking to the next level: reducing our water consumption and increasing our flexibility.
What do you think? Is a composting toilet right for you? Let us know in the comments below!
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