Sewer Tank Odor in RV Bathroom and Cargo Area?

[boyscout]

I also saw something about a formula using Calgon Water Softener and another product to add to the tanks to clean them...but can't find what the exact formula is...anyone tried that and can give me the correct formula if so? Thanks for your comments!

You've probably seen references to something called the "GEO method" and if you search for that you'll find descriptions.

I use it frequently - Borax or Calgon water softener and Dawn dish soap. There's not much of a "formula" - I probably overdo it and put anywhere from one to two cups of each in the tank along with a couple of gallons of water after dumping. I believe it works; our sensors are still generally useful after months of living in the trailer whereas those in our last GD trailer (without using GEO) were useless almost right away.

I'd guess that GEO is less effective as a means of controlling odor than it is at keeping the tank relatively clean of debris and oily films. We recently experienced an odor problem like yours despite frequent GEO. After our daughter and family used the trailer for a very hot week and got the tanks pretty full it was noticeable in the trailer for the first time. I dumped *and* installed a new Studor vent that I'd had under the sink for months after reading here that they often need replacement. The smell was gone the next day.

If I had known that the Studor vent easily screws into place - unscrew the old cheap valve at the top of a PVC pipe under your sink, screw in the new one - then I would have done it months ago and *maybe* not had the odor problem. It's probably worth the low cost of removing that variable. This is the one to buy:

https://www.homedepot.com/p/STUDOR-1...0341/202275238

Finally, I've seen a couple of favorable reports about this product:

https://www.amazon.com/s?k=odorlos&ref=nb_sb_noss_1

I ordered some, but am currently in a dispute with Amazon and seller ShopEddies.com for shipping me damaged and questionable product, so I haven't tried it yet. Others may jump in with their favorite products for making sewage smell like roses.

Good luck.

[Chiefblueman]

Keebler posted the Geo method link in post 6. I use it, including the bleach, before we move on or go home. Maybe not every time I dump. As often as I reasonably can for the black tank, usually just on the last dump of the trip for the greys. The AAVs are pure junk from the factory. I had some odor from new. Replaced them with Studors. Upon forensic examination I discovered the cheap factory units would not always seat properly. Junk. I have no odor issues. Haven't had any dump valve issues. Hope I didn't just jinx it.

[terryannbautz]

Thank you so much!

[emessmer1]

We have owned our 2016 Reflections fifth wheel 337RLS for about 18 months now - we bought it gently used. My question is regarding getting rid of the sewer odor or is this just something we have to deal with? The sensors for the black, sewer tank have never worked, and now the two gray tanks also do not show empty when dumped (my husband says this is common with RV tanks.) We know it is time to dump because of the odor, which can be smelled from inside the bathroom, kitchen area and also in the cargo area below the bedroom, which is accessed from the outside. After dumping the black tank, I have the hose hooked up with valve open and rinse out the black tank until it runs clear, then dump the two gray tanks. I then put 1-2 Camco MEGA All-in-One sewer Tank Treatment in the toilet and flush down with water. It still smells after I do this, but usually after about 6 hours or so the smell goes away. I just wonder if this is normal or if I should be doing something different? I wonder if having the tanks professionally cleaned out would help...does that help the sensors to work again? I also saw something about a formula using Calgon Water Softener and another product to add to the tanks to clean them...but can't find what the exact formula is...anyone tried that and can give me the correct formula if so? Thanks for your comments!

So, having the smell when it starts to fill is not unusual. We get a solid 6-7 days in Florida when vacationing and that's usually with external temps of 91+ and internal to the RV temps of 70-74. Make sure you're using an organic chemical (one based on enzyme producing dry bacteria), NOT the formaldehyde based chemicals (I'm not familiar with the Camco one you called out but I'd bet it's non-organic, which means what it is doing is using high concentrations of sodium (not table salt, that's NaCl, but SODIUM which is just Na) to break down the paper products. It also has a limited effect on the organics you put down the hole. The biological style packs handle the issue differently. They produce paper and black matter eating enzymes and bacteria just like a real septic tank.

Now, an error you are making: You run the water until clear? Nope. Not even close to clean a lot of times. Dump your lack, run water until clear, fill that sucker back up to at least 2/3 full again and re-dump. You will almost always see black matter float by. Let's face it, I have a 42.5' RV. Environmentally friendly is not something we set out to be when we bought a trailer that takes 7.8MPG to pull. I likely go through 400-500 gallons of water for ever black tank dump. And I have no smells afterwards. You have to remember that due to the way the tanks need to be mounted, their design SUCKS! They are almost always flat bottom tanks, leaving plenty of room for a black matter or 2 to hide out in a corner or high spot as you stop running water b/c you think you're empty.


Another thing I do is bounce the tank.... If I'm dumping, I'm almost certainly hooked to the truck. That leaves you fairly level.... Remember that flat bottom tank I called out above? Use your jacks to push the trailer to a +1degree front to back, left to right and fill I up a bit again. Level it all after you finally stop seeing stuff come out so it can drain naturally.

Hope these tips help. Second RV and 3.5 years into this lifestyle. Yeah, I'm a total newb compared to a lot of the guys and gals on here but my tanks don't stink so take it for what it's worth.

[emessmer1]

Regarding the formula for Calgon, there are a number of different opinions out there on a formula. Here is one: https://sites.google.com/site/cbruni/

I have never tried it, but I am an advocate of pumping in 5 gallons of clean water after I do my thorough black tank flush. Once I am cleaned, I simply close the valve and let the black tank flush valve run a bit. I used to be more precise and measure how much water I was pumping in. I don't take the time to measure anymore. I used this: https://www.amazon.com/Rainwave-RW-9...s%2C137&sr=8-3

If I am at a full hookup and have time, I will squirt (no measure) some dawn into the toilet before adding the ~ five gallons of water. I feel like this water and detergent sloshing around until the next trip can't hurt anything.

Well, you are right and wrong all at the same time. If you're using the formaldehyde based black tank treatments it'll likely harm nothing to have that detergent in there. However, if you're using an enzyme based treatment, the detergent will likely kill the bacteria that produce the enzymes that actually break down the TP and associated black matter. Same reason you shouldn't ever put bleach into a septic system. It's a living thing and if you kill the living part, you'll have hell to pay later. (A lot less hell in an RV... It'll just stink until you dump and clean, but for a septic system it can kill the entire system).

[Houndbb]

Formaldehyde? TP + formaldehyde + organic Baby Ruths = ?

Mummified poops?

Seriously, who buys products containing formaldehyde anymore?

[emessmer1]

You'd be surprised. It's on every big-box store's shelves and a lot of people are not educated enough yet to know better. I didn't know better 3.5 years ago and used it on the 1st trip out b/c that's that the dealer handed me. GDRV includes that same type of stuff on new purchases too. We had 2 freebies under the counter when we bought the Momentum last year. I simply tossed them in the trash. My only guess: It must be cheaper

[DebbieT]

Black tanks are a stinker to take care of. We put 5 gallons of water, 1 cup of Dawn, 1 cup of water softener and the toilet chemicals. Driving down the road this will slosh around. When we get ready to leave, we use a Flush King to back flush from the outside. You can have someone open the toilet on the inside and time how long it takes to get near the throat. Now you know how long to do it outside be yourself.

[emessmer1]

Be cautious of this method. If you're not running the same water pressure inbound to the flusher each time you do it, you may well overflow the bowl if you end up on a high pressure hose compared to what you timed it with.

[Booneyrat]

My 2017 337RLS had the same smell problem,after looking into it I found the black tank vent pipe is horizontal to the roof at the top so when the vent pipe gets condensation in it,especially if it's cold out,the sewer gas has no place to go.I installed a Tornado vent cap,but it did little to "fix" the problem.It's another bad design from GD.