The Magic Of Microbes Holding Tank Treatments
You might think yours smells like roses, but all poop stinks. There’s no getting around this smelly fact of RV life but after twelve years full-timing, I’ve finally found a great way to eliminate its offensive odors. From now on, my RV wheels will never turn without the magic of microbes holding tank treatments.
Lots of people claim their tanks don’t stink, but I’m not one of them. Allow me to get real and share the gory details about how our holding tank odors got offensively rank when the temperature goes up or the tanks get full, whichever comes first.
How microbes invaded my home
Like many people, I used to think that holding tanks worked like residential septic systems, which break down solid waste. But wastewater holding tanks have always been nothing more than a box where liquid and solid waste was get stored until the RV was taken to a sanitary dump station. Once connected with a hose, the RV holding tank’s contents get emptied put into a real septic system.
Towing all that poop around is stinky business without an effective holding tank treatment. Some people say they don’t use any treatments at all and smell no odors. How I envy their olfactory myopia. In our RV, holding tank odors are as real as that burrito I ate last night. Despite our fastidious attention to holding tank maintenance, on warm or windy days black tank odors can sometimes infiltrate into our living room area.
We often wondered why this happens and all we can think of is that our black tank is placed directly below the toilet, which allows odors to escape through the flange. It also doesn’t help that one of our ceiling vents is situated directly next to the sewer vent. The combination can be noxious.
As full-time RVers for the last twelve years, we’ve had plenty of opportunities to try out different holding tank treatments. From the all-natural geo method to traditional holding tank chemicals and everything in between. But nothing has completely eradicated the stench of our black tank after seven days of use—until microbes creeped into RVing and changed everything.
The science behind bacteria eating bugs
We discovered the magic of microbes holding tank treatments after searching Amazon for highly rated products RVers use. The aptly named “Caravan Full-timers Holding Tank Treatment” caught my eye because it had a long list of unsolicited rave reviews. The enthusiasm prompted me to give it a try.
The product uses a “natural, eco-friendly, probiotic bacteria enzyme formula” to break down solid waste, which eradicates holding tank odors. The little microbes even clean your tank by crawling up the tank sides and top when you drive around, sloshing the liquids in the process. Caravan doesn’t want to give away their trade secrets so you won’t find any other specifics about this microbial-based approach.
Curious about how microbes kill RV holding tank odors, I did some Internet research on odor-eating bacteria. Here’s what I learned about the microbial odor elimination process in a 2010 article by the South China Morning Post newspaper.
The magic is mainly done by bacteria in the Lactobacillus family, which is used in the production of yogurt, cheese, beer and chocolate.
Lactobacillus feeds on human waste, releasing lactic acid that eliminates the growth of most odor-making bacteria.
Microbes literally eat poop to get rid of black tank odor. Of course, they also eat whatever else happens to be in your tank, like sludge build op on tank walls that block sensors. It seemed too good to be true, but then we bought a microbial-based product. After a couple of weeks, I noticed that it lived up to the claims.
Different microbes holding tank treatments yield different results. We have tried two different RV holding tank treatments since discovering the magic of odor-eating microbes and are happy with the Caravan Full-timers Holding Tank Treatment
You may find that other products work better for your rig. Here’s a couple of top-rated products to get you on the path to an odor-free RV adventure:
Caravan Full-Timers Holding Tank Treatment
- Convenient, no mixing or rinsing
- Effective, no odor, plugging, undigested waste
- Maintain working sensors
- Safe for people, pets, septic tank, environment
Unique RV Digest-It Holding Tank Treatment
- The safe, earth-friendly formula works quickly to liquefy waste so your tanks empty easily and never backup. You can even stop using expensive 1-ply toilet paper.
- Eliminates odors without masking using the perfect bacteria-enzyme blend.
- Cleans sensors and lubricates seals and valves. The non-toxic, earth-friendly formula contains advanced cleaners that ensure your level gauges remain working properly and your valves and seals stay lubricated and working properly.
Traditional RV holding tank deodorizers of the past pale in comparison to microbes holding tank treatments. Let us know what you discover in the comments below.

Rene Agredano and her husband, Jim Nelson, became full-time RVers in 2007 and have been touring the country ever since. In her blog, Rene chronicles the ins and outs of the full-timing life and brings readers along to meet the fascinating people and amazing places they visit on the road. Her road trip adventures are chronicled in her blog at LiveWorkDream.com.
Think I’ll keep my composting toilet in the RV, don’t need any chemicals.
I also use Happy Camper with great results but will try the microbial products to compare.
Loren we used Happy Camper in the past, but found this one worked better for our tanks. Good luck!
Temps higher than 85/90° kill the enzyme organisms. I have to Happy Camper in the summer.
We use Tank Tech and it has been working great but it is a little pricey.
Hi Rene the headline on this stated about using RV Digest-it & Happy Campers together but I can’t find what you said about it or how much of each one? Do you think the Caravan digester is best all around? I appreciate your time with my questions. Have a wonderful day. Kind Regards,
Ginna:-)
Microbes are not chemicals. I agree, I don’t like using harmful chemicals anywhere in my life if I can help it.
We use “Rid-X” and also “TST” orange. Virtually no odor. I have a clear 90 deg. waste hose fitting – no solids or paper of any kind. Also cleans grease and oils from tank walls. Follow directions and cautions. (19.6 oz. of Rid X treats a 1,500 gal. septic system – use appropriate amount for your holding tank! I use about 3 or 4 tablespoons for each of our Class A 50 gallon tanks. Put in thru the drain, flush well; and the toilet. Keep water or anti-freeze in your toilet to act as a trap between tank and valve.
I do the same and never have had a problem.
Im the Rv Proctologist of South west Arizona. Those are good treatments. But i also recomend for a forty gallon tank. Always put 5 gallons of water and a cup of Dawn dishwasher soap. It makes the tank slippery. So the goods slide right on out.
Rene– Thanks for the article The Magic of Microbe Holding Tank Treatments. We’ve been RVing for more than 13 years now and are not fulltimers but do our share of long time rving. I’ve seen many an article on the subject of black and gray tank odors and yours seems to be right up there with the best of them. I will give your two suggestions a try but I have also been using another product for this same purpose and have had no problems with it and the breaking down of the waste that goes into the black tank or the grays. I’ve been using Happy Camper for the past 8-10 years now and have had extremely good results with it. No odors and in most cases all the waste has been broke down to liquid form. Happy Camper comes in a powder style and I use it in both the black and gray tanks. Since I have a 55+ gallon black tank I do use more than one scoop in it but aside from that I do as directed as per instructions on the container with, as I stated earlier, great results both in the colder season camping and the hot summer camping. You might want to give it a try also and see if it compares to your two recommended Microbial solutions. Thanks again for the article!
I use the digest it and have no troubles with smell or emptying. Great stuff!
Pure Power is also a great black tank digester. Microbiological, controls odor, keeps tank clean, inexpensive, 2oz treats your 40 gallon tank.
Using up the last of our “Happy Camper” it worked OK, but Unique’s RV Digest-It works much better. So, I ad one scoop of Happy Camper and 4 ounces of RV Digest-IT.
No smell at all! And everything is turned to liquid. Plus, it is not a Chemical, it’s made up from natural enzymes that break down waste!
Have been using Unique RV Digest, for a while and it works GTEAT……When I winterize my 5er, I fill the tanks and pour a quart into each tank and let set overnight then dump them….Tanks are cleaned AND the tank sensors actually work when we take it out in the spring…happy Campin….
This article is great for full-time RVers with large holding tanks, but what about those of us that aren’t camping all the time. We’re currently using Happy Camper (used it successfully for ten years in our houseboat in very hot weather) but the microbial products sound very interesting. Are they worth it for smaller tanks that are emptied once or twice a week?
I was wondering if you could just put plain unsweetened yogurt down the toilet? It has the same microbes…
We are not full timers so we dump every 3 – 5 days when snowbirding. Is that ling enough for the microbes to work effectively?
Bill, it’s been my experience that once you use that treatment a couple times, 3-5 days is definitely long enough for the microbes to work.
Both links above lead to the Unique product. Do you have one for Caravan’s?
As a full-timer and and RV owner since 2007, I don’t see the need for this product, unless maybe you’re not adding enough water to the tank when flushing and too many solids are accumulating, or the tank has been sitting for awhile without being emptied. Realize that hat goes into the holding tank does not need to be turned into a ‘slurry.’ Wastes don’t need to be broken down. They just need to fit through the 4″ dump valve. I use chem tabs that are safe for septic systems and they do the job.
I like reading about the perceived effectiveness of these various treatments, but what really works and how? It would be more believable if the manufacturers would publish the actual ingredients of these products so one could compare chemistry, potency, and cost to volume used. many products today pay for fake endorsements and they would be easier to sort out if the chemistry was published.
I wonder why the same treatment used for house septic tanks will not work? Also, many years ago people used to put a plain old container of Fleishman’s yeast in the toilet once a month to take care of this problem. Any thoughts?
I never thought of yeast…I was thinking plain unsweetened yogurt, or just the acidophilus culture that you can buy in an 8-16oz bottle.
I use the Unique Products, and they work. When using Unique’s Digest-It, or Caravan for that matter, be sure to never use a bleach product to clean the toilet. It will kill the microbes. If you listen closely you can hear them scream!😱
Unique has a toilet cleaner that not only eats the bacteria and removes stains, but it is also a tank enhancer, because when you flush, those microbes just Drop down and join the others. Oh what a wonderful thing. Give it a try. I think you will be very happy with these products.
Funny I remember at a lake camp in the Mtns we had latrines and had to ‘feed’ them 1 a week with dry yeast product so this must be a tried and true method. We get our 1st RV next month so this is what I will use
Yes; see my comments on using “Rid-X” septic tank treatment……
What do you suggest for cleaning the toilet since most products contain bleach?
We use this to clean the toilet. It works great!
Unique Natural Products Safe Toilet Bowl Cleaner, 24-Ounce.
I found it on amazon
As a van driver I wonder if this would work in a 3 gallon porta-potty. Any ideas how long it takes to dissolve solid waste? Thanks
Hey Doug, no idea but I think the longer you use it the faster it works.
That is probably true Rene. However, I am not sure how hardy the mircrobs are in a reduced liquid volume and -20f to – 30f outside storage over the winter months. Anyway, the Rid-X works for us and it doesn’t seem to take long – like between stops and dumps usually weekly; or every couple days on the road.
We’ve been using the Unique RV Digest It for 10 years in three trailers. It’s all we use.
These products have 4.0 and 4.2 stars (out of 5) on Amazon. I think I’ll stick with Happy Campers which has worked very well for us, and apparently many others, since it gets 4.6 – 4.8 stars (depending on the size of the container you buy) on Amazon. It appears to be economically about the same as Caravan’s product, but less expensive than Unique RV’s.
Hello, the article forgot one great product. TankTechsRx All natural microbes and been around for years. Check out their website https://tanktechsrx.com/ or @TankTechsRx. This will help with more than just a smell.
Cool article. Having recently lost my pet, I’m gonna start naming my poop tank microbes and feeding them every day. Much easier to care for, and no vet bills!
How long do these products take to work. I am suspicious based on my knowledge that I would be emptying my tank before there was much if any colony of bacteria.
Good article thank you. We’ve used Unique and Happy Camper and had no luck with either one – I actually threw out the bottle of Unique after trying it a couple times. We use the TST blue pods and they seem to work well, no clumps of anything when dumping the tank, but when the tank level gets up there the smell does appear occasionally. Once in a while I’ll put some Dawn and Calgon in there to try and clean the sides, but our tank sensors are external so we don’t worry about those as much. Thanks for the info!
We purchased a new 2020 Tiffin motor home and went on our first trip in May. We’ve owned travel trailers in the past, so we just purchased RV Holding Tank Treatments. Well, the odor was so bad that we really thought something was wrong with our new RV. I used this Walex TOI-91799 Deodorizer to remove odors like sewage after one day of 90-degree weather camping. It dissolves quickly, thereby treating the tank quickly. It is available in a non-staining color, which also works efficiently in breaking down waste and paper and deodorizing the tank pretty fast.
Another of its most impressive qualities is its fragrance. It’s known for using the strongest formula for odor control available in the market.
Another of its most impressive qualities is its fragrance. It’s known for using the strongest formula for odor control available in the market.