Tips So You Don’t Get the Poo Pyramid of Doom

Dealing with the ‘waste’ that is created during a trip is probably one of the biggest fears that people have when first getting started in the RV world. Having the ability to just simply flush a toilet that is connected to the sewer system is one of the great luxuries of living in the modern world, as most of us don’t even think about what happens next. However, when you travel in an RV, that waste suddenly becomes your problem, so it is important that you know how to handle it properly.

Poo PyramidThe good news is this – those who have used RV’s for a long time know that there isn’t really anything to worry about when it comes to the black tank. As long as you regularly maintain your system, including using some of the tips below, you should be able to avoid any serious ‘poo problems’ down the line.

Always Have Water in the Tank

This is what you could consider the ‘golden rule’ when it comes to the black tank. You need to have water in the tank before using the toilet so that the water can serve the same purpose as it does in your toilet back home. The water will help to reduce the odors that come from the tank, and it will allow waste to move along when you are draining the tank out. Without water, there is a very real possibility that some of the waste will get stuck – and that is a messy problem that you do not want to deal with.

2014-12-12_0541Periodic Flushing Required

Obviously, you are going to need to empty your tank at the end of a camping trip – or, possibly, during the trip depending on how long you are gone and how many people are using the RV. However, the emptying of your tank alone is not going to be enough to keep it clean. Additionally, you will want to flush the tank from time to time in order to wash out anything that may have been left behind from previous trips. Most of the modern RV’s on the market today have a flushing system in place, which usually just requires a hose that is carrying fresh water. As long as you stay ahead of the game on this maintenance task you should be in good shape moving forward with the blank tank.

Get Help from Chemicals

There are a number of environmentally-friendly chemicals on the market which have been designed to be added to the black tank in order to break down waste and keep a limit on odors. These chemicals are simply added to the water that you already have in your tank, so this is a task that shouldn’t take more than a moment or two to complete. Simply follow the directions on the container that you have purchased and you can rest easy knowing that this chemical solution is helping keep your waste collection moving in the right direction.



  1. A seasoned camper advised me to occasionally dump a bag of ice cubes down the toilet. As the ice melts, it scrapes everything clean. I’ve added some baking soda, borax and essential oils for deodorizing and cleaning as well. It works great.

      • Electrical works great for a travel trailer and fifth wheel.. bit does not work for a motor home. It’s all in the bounce motion.

      • actually if you put the ice in the tank before you hit the road, the ice will bounce around/float and it will help…. however if the poo has been left in the tank to dry over an extended period of time then your going to have to spend a lot more time flushing

      • Actually Rob, the ice trick works great in a towable because of the movement of the trailer when towed. Totally different movement in a motor home. The video showing the tank in the bed of a pick up and it not working is the same principle as a motor home. If you are in a towable, go for it with the ice…

  2. One point to add to Laura’s suggestion: Add the ice just before you head down the road. It is the motion of the cubes as you drive that does the scraping.

    • I agree add the ice before you drive. We dump black tank at dump station. Add a couple bags of ice and drive home. According to the remains coming out I would say it works just fine.

  3. Also failed to mention that when at a site with full hook ups, do not open the sewer drain right away. Start with a few gallons of water in the black tank and do not open the drain valve until leaving or near full. This will help keep the poop from piling up and hardening. 🙂 Happy Camping!

    • We have been nearly full time for six years in our Class A. We use this tip and do mot have any problems. Also, hubs flushes the tank for a good while after each dump.

  4. I would be a little careful adding so much stuff may make your take a gunkey mess that you can’t get all the slug out the ice is good the oils I would stay away from dish soap would be a good cleaner with some hot water

      • Me too. I’m stationary so this helps with the smell too. Make sure that you’ve gotten everything but the water out before dumping.

  5. A bag of ice in the toilet, once around the block before dumping the load and it should help loosen any stubborn particles. even then we use the actual toilet to blast down through to the tank as well as the tank flush connection out side. Before the trip I usually pour about 2 liters of water and a deodorizer in, this keeps washing the sides while in motion as well as the sensors. Nothing worse than a sewer gas back flow and a terrible odor in the RV. Good travels, enjoy the choices you make…

  6. I have heard that you need to keep some water in the black tank but my question is how much? An inch in the bottom? A gallon in a 60 gallon tank?

    I have also hear about the ice in the black tank. Supposed to slosh around and clean the junk off the sensors.

    • I always add 5 gals. of water before I use the black tank. 5 gals out of 60, is not that much really by the time it’s distributed across the entire tank bottom. I add Calgon water softener too, it helps “coat” the tank, helping it prevent “stuff” sticking to it.

  7. I installed a Tornado (that you can buy from Amazon) and it does a very good job of keeping my black tank clean.

    • Give some more information on this ‘Tornado’ you installed. A link would be nice or the manufacturer might help, as when I searched for Tornado I got a lot of various movies to pick from on Tornado’s, I don’t think they would work very well.

  8. Bert, Camco “TORNADO ROTARY TANK RINSERS”. It’s a permanent tank risers that feature 360′ rotating heads to clean your tank. Go to Camco site they are a very big outfit for RV’s.

  9. When I had a sewer system at my past home, a plummer gave me advice to drop a small amont of yeast down the toilet with water. This keeps the waste from building in the system. I wonder if thar would work here?

    • NO…….. This works great for long term in a septic system. RVs have a holding tank not a septic tank. It takes several weeks for yeast to grow and actually start braking down waste.

  10. i bring the hose around to the inside of the bathroom and spray water down the toilet while spraying pine sol down. This does a super flush that seems to work well.

    • Did you ever read the “caution” label of Pine sol ? It says not to use on rubber! Your seals are rubber. It will deterate them.

  11. Also, ad some good bacteria and enzymes to the black tank water before using the toilet on your trip. This will help to naturally break down the waste… Good luck!

  12. Please allow me to make some comments on this subject based upon more than five years of motorhome travels. The dreaded pyramid of poo is most likely to occur when an RV’s black water tank is hooked up long-term to a campground’s connection and the valve to the sewer hose remains open. That arrangement does not allow water to accumulate in the tank, thereby creating a condition that can allow poo to pile up and dry out. As others have suggested, having water in the black water tank can prevent that dry condition, but that means NOT leaving the valve open all the time when parked at a campground with full hookups.

    Using lots of water when flushing poo also helps but I take two additional steps which reduce potential odor in my coach. The toilet in my coach rarely leaves more than an inch or two of water in the bowl after flushing. Prior to doing #2, we add enough additional water to the toilet bowl, so it works more like a conventional household flush toilet. When poo is under water it’s far less fragrant and we have the additional benefit of having the extra water in the bowl to aid with the flushing process. In the confined space of an RV, controlling bathroom odor to avoid offending others can be a challenge. We use a product called POO-POURRI Original Citrus available from Amazon. Spraying a couple of puffs of that beforehand will neutralize much of the odor.

    Like many RVs, our motorhome did not come equipped with a built-in tank flushing system. My solution was to buy an inexpensive flushing wand from Wal-Mart. It’s a length of PVC pipe that has a hose connection and valve on one end and a cap on the other with four holes drilled at the end of the pipe to produce a horizontal spray when the pipe is inserted vertically through the toilet and into the tank below. When our black water tank needs flushing, I hook the wand to my hose for non-potable water which I route through one of our coach windows and into our bathroom. The flushing wand is long enough to reach to the bottom of my black water tank but the horizontal spray also works well to clean the tank’s sensors.

    • Can be made for less than $15 at your local Home Depot sprinkler department using pvc parts. Works great. Highly recommended.

    • The rigid wand works great on tanks that are directly below the toilet. Most 5th wheel tanks are not right below the toilet. There are flexible wands on the market but they have to be long enough to reach your tank. Luckily, our fifth wheel has the built in sprayers. Our prior fifth did not. We flushed with lots of water, only used RV toilet paper, used chemicals and Calgon, always traveled with some water in the tank to slosh around. We didn’t find ice to be of much value because it melts so fast. Lots of water when flushing a poo is the main hint and the enzyme “digesters”. We’ve never had a problem.

  13. Everyone seems to have an opinion on the black tank, and I have mine. The pyramid is usually the result of not using enough water and using to much or the wrong type toilet paper. ALWAYS use plenty of water when flushing. If you do get this pyramid, use HOT water to loosen it up. HOT water works best. Best plan is to learn about the black tank and how it functions and make sure all that use it understand it also. NEVER lever the black tank valve open when hooked up if you do the waste cannot be carried out of the tank properly, will dry and harden and you have a nasty problem to deal with. I have been camping many years and never had a problem. I dont use chemicals in my tank, I use Dawn dish washing liquid. I add Rid-X when my coach is parked at home and I always flush system after each trip and get it as clean as I can and leave about 10 gallons in each tank. Proper use and maintaining the system will save work. I start each trip with about 10 gallons or so in each tank. With the Dawn in the tanks, this sloshes around and helps keep sidewalls clean. A lot of folks may not agree with this method, but it has worked for me for many years.

    • People always say not to leave the black tank open, but, I am on my 3rd rig over many years and it seems the only time I have an issue is when I close it. Makes my place smell like an outhouse. I can’t stand it. I uses precautions though… I don’t flush my toilet paper and when I do go number 2 I add lots of extra water and flush down a quart or 2 of hot water afterword’s to make sure that everything has flushed out . I’m a full timer and have done it both ways and this works best for me.

      • If you are getting a foul odder in your RV, Make sure you DO NOT have the Vent fan on as it will pull air through the tank Via the Vent system whether the Drain valve is open or not. Hope this helps.

  14. I do something totally different, I fill my black water tank with water and leave it there for a week before I go away and then i drive to my first destination and empty my tank before use. This certainly stops any problem and I repeat the process on the last day of my trip. I am lucky enough to have my own dumping station which helps.

  15. I put my TP in the garbage next to the toilet. We add extra water often. When we turn our shower on the cold comes out first. That water goes in a basin in the shower and we add that water to the toilet. We use chemicals and we have the wand in hat you can put down a the toilet. I’m using my dishwater also. If there is any pit toilets near we use them rather than the trailer. So far things are lose enough.

  16. There is a new unit called SolAir which totally eliminates all orders and also disinfects the tank. Some dealers can install this.

  17. For many years I have used amonia,every now and again before traveling fill the tanks half full of water and add a couple of liters of ammonia to each tank.Dump when you arive,and you will be astonished how much residue will have been removed.

  18. We Are First Time “RVers” , With A Recently Purchased 2018 Grand Design “Reflection” 28BH !!
    Appreciate All The Valuable Info & Experiences , Thank You All
    We’ve Decided To Never Use Our “Black-Water” Tank By Purchasing A “Composting Toilet” Made By
    “Natures Head” , We’re Hoping That This Will Resolve Not Only Excess Weight Issues & Also Cleaning & Odor Issues ???
    I Would Really Appreciate Any & All Comments Regarding Our Choice In This Method Of Eliminating The Conventional Toilet Facilities In RV’s From Experienced Users Of “Composting RV Toilets” & Also Questions From People That Do Not Presently Use “RV Compost Toilets” …..Pros & Cons !! ??
    All Opinions Are Appreciated . It Seems That This New “Space-Aged” (International Space Station) Method Would Be The Solution To Eliminating Allot Of The Present Enviromental Uses & Maintenance Issues That I’ve Read Above !! ??
    Thanking You All In Advance For Your Valuable Experienced & Non-Experienced Opinions Regarding Our Decisions .
    Happy Camping & Drive Safe
    Ken & Lu

  19. I put a laundry soap pod in while driving and it softens and cleans anything left in after dumping. My unit has a flushing hook up on the outside that you hook the hose to but it doesn’t always get it all.