By Gail Marsh
One of our readers, Gary H., recently wrote to us about RV toilet paper and said: “We have only been RVing for five years, so we are always open to new ideas. We tried your suggestion and used the Kirkland brand of toilet paper while on our latest excursion. Unfortunately for us, it seems to be a disaster. We have never had an issue draining our tanks in the past. However, when I tried to drain my tanks last night, very little came out of the black water tank. I have a septic company coming out this morning to pump my tank as it is almost overflowing. I can only surmise it was the toilet paper switch.”
You may be right, Gary. I’m really sorry you’re having a problem! Maybe the Costco Kirkland brand toilet paper did cause your problem. Since the pandemic last year, and the subsequent run on toilet paper (no pun intended) several people have complained. According to Reddit, not only have folks had problems with the brand causing clogs, but others have also fussed that the Kirkland brand is much thinner than before. (Hard to believe how they could make it any thinner and how the thinner paper could subsequently cause clogs, but there it is.)
I researched the Kirkland brand and found nothing to show that Costco changed its 2-ply paper thickness or bio-degradable capabilities. It could be that during the pandemic something changed with the rush to fill the overwhelming demand for toilet paper, but I couldn’t find it.
Your letter made me think. There are so many different variables when it comes to dealing with the black tank. The type of toilet paper is certainly critical. The designated “RV toilet paper” is so expensive to buy that we’ve experimented with several different brands over the years. You can run your own unofficial test like this: Use identical containers. Fill each container with the same amount of water. Then put four squares of “X” brand toilet paper into the first container, four squares of another toilet paper into the second container, and yet another toilet paper into the third container. Stir each container briefly. Watch to see which brand of toilet paper dissolves first or breaks down the best overall.
Here are some additional tips regarding RV toilet paper
- Look for RV, marine, or septic-approved toilet paper or test a non-specified paper for solubility like described above.
- Buy single-ply tissue. But remember it defeats the purpose if you use double the amount of toilet paper. If single ply doesn’t do the job, you may as well use double-ply paper.
- If you use chemicals in your black tank, be careful how you clean your toilet bowl. Chemicals that clean your bowl can also kill the good bacteria in your black tank. These bacteria are needed to break down the waste and keep your tank from emitting strong odors. The bowl-cleaning chemicals may also cause an unintended chemical reaction with the chemicals you’ve put into the black tank. You can use baking soda and water along with your toilet brush and still get the bowl clean and fresh.
- Be careful what you put in the toilet. I used to dump mop water down the toilet in our RV. This is not a good thing to do! Not only can the cleaning chemicals upset the balance of useful bacteria in the black tank, but any debris from the mop water can stick to the sides of the black tank and potentially cause a clog over time. Nothing should be put down the toilet except waste and toilet paper.
- Avoid folding the paper into layers when using. Often the paper will remain folded when flushed and will take longer to break down.
- How we use toilet paper makes a difference, too. Try to avoid using too much. Four squares should be enough, but if more is required, flush first before adding more paper.
- Use plenty of water. The toilet is not the place to skimp on water. Any brand of toilet paper needs adequate water in order to break down and pass easily through pipes.
Related:
Is reusable toilet paper a good idea in your RV?
##RVT1002


My admittedly unscientific conclusions about the cause of TP clogs are: (1) people don’t use enough water when flushing, (2) don’t add water to tank before dumping and (3) some even keep the black valve open throughout their stay.
I would agree 100%
We NEVER put paper down the toilet of our RV. We use scented diaper bags to place our paper in. I have seen too many clogs caused by the paper. Unfortunately many new RVers don’t learn about RVing before hitting the road and think the toilet in their RV works just like the one in the house.
We’ve been traveling 25 yrs, 2 motorhomes, latest 19 yrs, 275,000 miles total. Never, so far, had a problem. We use RV recommended toilet paper. We broke down and buy the expensive one, as it is 2 ply, so we use less and more comfortable. For all the money we spend RVing, that is a small part of expenses. We add water after flushing, so not starting with an empty tank. Use back flush feature after flushing, every time.
We haven’t put TP down the toilet in any of our trailers in over 12 years. We have a step can with a lid and a garbage bag in it. Every day I take out the bag, toss it and put in a new bag. This way we can use any kind of toilet paper we want. Also those moist bum wipes.
Some people find it gross but we NEVER flush TP in the RV toilet and we lived in ours full time for 10 years. I have a small garbage can with liners beside the toilet and we put all used TP in it and dispose of it with the garbage. Think what you will but we never want to deal with a clogged-up black tank.
This is similar to what we have beside the toilet. https://www.amazon.com/mDesign-Rectangular-Wastebasket-Container-Bathroom/dp/B079B5LX59/ref=sr_1_31?dchild=1&keywords=small+1+gallon+garbage+container+for+kitchen&qid=1622298876&sr=8-31
Only 4 squares??
That was my thought exactly!
Best advice is use lots of water, flush often. Been doing that for 25+ years, never had a problem, using regular household T.P. Hard to imagine putting the TP into anything but the toilet.
I use Member’s Mark from Sam’s Club. I tested it by shaking some in a jar of water and it completely dissolved very easily. I have not had any black tank problems with this in 10 years. It is 2 ply and very soft. Highly recommend.
Same here. We have used Members Mark for years. It passed the jar and water test. Never a clog.
All this talk about shaking the jars to “test” TP…? Before dumping the tank, how many drive over gravel washboard? So where does this shaking come into the picture?
The TP gets ‘washed’ into the tank, sits there until it is drained from the ‘bottom’… no agitation.
I agree with others, use a waste bin beside the toilet.
Don’t need a gravel road. It is tough to find a smooth interstate these days.
The minute you move your rig, the liquid in the holding tanks is agitating. I will add that putting used TP in a waste basket and ultimately in the garbage dump is not healthy or sanitary. Don’t even ask my wife about this concept. As noted, water (lots of it) is your friend. The more water in the tank, the better it flows when you dump. Adding a tank deodorizer / treatment (or water conditioners) helps dissolve TP and solids which makes the whole system work better. Water, water, water! And always add a few gallons of water to your tank after you dump and add the treatment. It will help keep the tanks working correctly.
We’ve been using Kirkland paper in our RVs for years, never had a problem. Possibly other issues preventing complete evacuation of the black tank.
As John C commented, water, water and then more water and if you are not sure, more water. One of the easiest ways to block up a black tank is to not use enough water. If you are not sure about it, just have a look in a dry vault toilet.
Richard.
Thank you so much for that “picture,” Richard, as I’m eating my brunch. 😯 Have a great day. 😀 —Diane
I think it’s really more about how you use your toilet than it is the toilet paper.
A bidet will drastically reduce the amount of TP you need to use. The water use is minimal just a cup or two and it goes to help flush the toilet so it’s not really extra water.
I was going to say the same thing! Best “upgrade” we’ve done.
I cringe every time I see someone mention the bacteria in their black tank. I think they are confusing septic systems and holding tanks. Nothing sits in my tanks long enough for bacterial activity, however beneficial, to have any noticeable effect on the contents. I do use tank additives for odor whenever that problem arises, but it seems to be related mostly to what goes into our personal food processing systems than anything else.
Bacterial action is going on all the time. Under ideal conditions, some bacteria reproduce (double their population) in as little as 20 minutes, and it is going on in any damp spot in your tank – as well as on your skin and in your gut. As long as there is plenty of air available, there shouldn’t be much odor.
We have used both Kirkland and Member’s Mark brands of TP plus we also use the Member’s Mark Flush-able Wipes in our on board septic system. In the 17 years of use with most of those while Full-Time RVing we have never even come close to having a clogged up 3 inch black tank line. Can’t say the same for our grey tank with it’s 1 1/2 inch dump line and valve. Why they didn’t use the same size on both baffles me to no end. I guess my common sense must be different than theirs.
I was told the reason for the size difference was: grey water is not suppose to have lumps in it and it helps people to know which is which. If the black and grey were the same size there are many out there that would get confused. It is true when you think about it. When my husband’s Alzheimer’s was getting worse and he couldn’t remember I put gray tap on the gray tank which helped him for a while. That would be a good idea of for manufacturers too – make the gray water tank handle gray.
Most trailers have black and grey handles plus stickers above each one telling you what tank it empties.
We have been full time for 20+ years. We have only used Scott Septic Safe TP. In all that time, no problems whatsoever.
We’ve never had a problem with our TP and we’ve used all types but make sure it says septic safe. As others have said, use lots of water. After dumping, I add about three gallons of water back into the tank with Happy Camper. Occasionally, I also add about a cup of Pine Sol on a travel day.
I lived full time in a 22 foot travel trailer for nine years, never used a black tank additive, used whatever supermarket brand toilet paper was available, and never had a clog. Some of that was standing still for extended times (keep black valve CLOSED until tank is at least 3/4 full before dumping) and some extended time on the road (don’t dump before leaving, allow sloshing around while traveling help liquify the “stuff”, including paper. As someone else mentioned, the “stuff,” including paper, does not stay in the tank long enough for bacterial activity to be much of a factor. Just soaking in the water and “sloshing,” even the minor amount caused by flushing, are the main liquefaction factors. Flushing dumps the contents of the toilet into the tank below with a “sploosh” that does cause some movement of the contents. On the need for a bumpy gravel road to get sloshing; On a smooth road even small movements will cause the tanks to slosh.
I used Scott toilet paper (single-ply) for years in my motorhomes and never had a problem. However, I did use enough water when flushing to keep any clogs or cement from forming.
Just did the test again on a few brands (after getting clogged that fortunately broke up with an additional 5 gallon bucket of water dumped down the toilet).
Tested our old Kirkland & Scott expecting good results against our Charmin only to find all of them held up fantastic. The only one (& our current TT TP) that broke up easily was Walmart green label – it was GONE after a bit of time & agitation & holds up very well for the necessary use
The “bacteria” in your Black tank will accomplish nothing. The Black tank is a temporary storage tank, not a SEPTIC tank. They are two completely different things, designed for different purposes. No waste will “break down” in the Black tank in any reasonable amount of time.
Totally wrong, Trent. The bacteria have no idea where they are, they break down waste wherever they find it.
Not totally wrong at all, Bill. It might–might–be possible to establish and maintain a healthy microbe population in an RV waste tank . . . but they don’t rely on that process. Most of them in the real world are bone dry between the annual trips to Aunt June’s house; no “population” of “good microbes” is surviving there.
Never had any problem. The only TP that ends up in the tank is that which has “residue stains” on it. This way, most of it goes into the trash.
Same rule at my sticks and bricks.
Back in 2015 we spent the summer in our RV, at my MIL’s house, while we cared for her. We were driving 10 miles round trip every 4 days to dump the holding tanks. Not good. Then we started putting the TP in a trash can and emptying it daily. That changed our capacity from 4 days to 10-11 days. Never looked back. I buy cheap anyway (Scott 1000 or equivalent) because I hate buying all the air that’s in the “plush” TP. We found plush stuff gets used at a roll every 1-2 days as opposed to a roll every week or so of the cheap stuff.
We used to use Scott 1000 or RV specific TP. My parents have been RVing for years and said they have best luck with Angel Soft. Recently, a YouTube RVer conducted a comparison test between Scott 1000, generic TP from Walmart, Angel Soft and RV/Marine Scott. Hands down, Angel Soft dissolved fully and quickly, even compared to the expensive RV paper.
I always test a new package of TP, before stowing away. Even if purchased before, you never know when they ‘quietly’ change the formula.
We have used the Kirkland TP for years with no issues in our RV. Use plenty of water with the flush. Also, ensure that you use a quality tank treatment to help break it down. We have used both Happy Camper and Unique.
I agree with Nick. I fill the tank to the first bar on the sensor before using and drop in a treatment pack. I started doing this after some nasty smells started coming out of the toilet.
We’ve recently discovered a toilet paper that dissolves MUCH faster and more thoroughly than all others we’ve tested, using the “water in a jar/shake” test. It’s Scott Comfort Plus. Our home is on a septic system and we now use it at home also. Not all stores in our area carry it, but we’ve found it on Amazon and at Krogers.
Here’s an important tip! Never ever put facial tissue down the toilet. Our SIL had a recent surgery and a drain was left. He had to clean this with facial tissue 3 times a day, without thinking as he cleaned the wound he would drop the tissue down the toilet. After the required amount of time to fill the black tank he went to empty the tank only to find it plugged. Eventually using a wire coat hangar and drilling a hole in the clear plastic drain elbow just large enough to fit the wire through he was able to unclog the valve. He said the first few seconds was nothing but the tissue that didn’t dissolve. The rest of the trip he dropped the tissue into the trash can. So if you are prone to dropping facial tissue down the toilet you better do a water test on your brand of tissue.
Angel Soft has worked great for us the last 7 years.
What a bunch of nonsense, the brand of toilet paper makes no difference. We’ve used Quilted Northern Plush for decades without a problem. Adequate water is needed and makes the difference. It’s a holding tank with a large outlet pipe, it’s NOT a septic system.
So true!!!
Interesting article on how things change! After testing some years ago, we’ve used Cottenelle at home and in the Rv. However, about two years ago, I noticed a change in design and texture and tested it again – I don’t know how long it took to break-up as I ended the test after :45 min.! Now in the motorhome we use the Dollar Store brand as it dissolves completely in about 20 seconds.
There seems to be a lot of discussion for clarification of a holding tank and a septic tank below. While a technicality would indicate a difference – the fact is when dumping your tanks into remote park facilities – those are usually septic tanks! So be kind to the hosts tank as well as your on-board tank. I also use Rid-X in our tanks – good for ours and theirs!
If you do decide to do your own toilet paper tests, be sure to add whatever black water treatment chemical you use in your black tank to your test jars. It does make a difference. Happy Camping!
I will not flush any toilet paper in the black tank even if it is considered safe. I use the heavy duty toilet paper from Wal Mart. This paper would never degrade enough for the black tank so I use my covered trash can lined with colored plastic bags for its privacy. It is tied and thrown in the trash. I know it may be difficult when boon docking, but I’d rather be safe than sorry. Also it is mentioned in a comment below to be kind to the hosts tank. I agree.