Sewage

[LEA777]

My partner insists that the black tank should be closed to outside sewer in RV park. And then once a week or so he will be empty tank. I find it odoriferous. Why not keep tank continually flowing into outside sewer???? 33’ 2018 Classic Airstream

[pmclemore]

If you leave it open continuously, you may find that the liquid has drained, leaving you with the dread "brown mountain" directly under your throne.

Black tanks work best when there is a lot to flush at one time. Then follow that with your gray water.

Happy travels.

Pat

[azflycaster]

Your partner is correct. By keeping the valve closed and dumping when the talk is full will ensure that the solids are carried away with the liquids. By leaving the valve open you may have a build up od solids in the tank commonly referred to as the "Black Hills".

Also, keeping the valve open will allow fumes from the sewer system to work their way into you black tank and your trailer

[Justinhb]

Both Az and PMC are right...recommend adding more deodorant in the interim and making sure the the toilet seal is intact...we recommend using the orange deodorant (TST) available at Wally world...

[Mollysdad]

Make sure, as others said, your seal is holding water. I used to put a little olive oil in the bowl. Also, the roof vent can blow right back inside if your Fantastic Fan is nearby.
I never use the toilet for, ahem, solids or paper. So the last time I drained the tanks, I had a minute of blue water followed by two minutes of grey water. No lumps.
Beyond that, check this video by "Changing Lanes". He scrubs the vertical pipe under the flapper valve.

https://www.youtube.com/watch?v=QvSAPtBC3Qw

[moosetags]

Your partner is absolutely correct! The number one rule of RV camping is NEVER EVER leave the black tank valve open except when actually draining the black tank. Leaving the black tank open will cause "black hills syndrome". This can result in having to replace the black tank. With the labor involved, it would cost several thousand dollars.


Brian

[Rich W]

I would add, if you have the Fantastic Fan on, open the other vent or crack a window, otherwise you'll pull air from the holding tanks.

[n2916s]

Originally Posted by LEA777

We have a 2018 Classic FB 33’ . My camping partner insists

He keep the valve to the black tank closed even while we have full time hook up to outside sewer. Then when it’s close to full, he will dump it. Any logical reason to do it this way?



Signed,

Odiferous 🤢

As Moosetags pointed out, leaving the black tank valve open will result in the liquids draining off, leaving the solids to harden into stalagmites of immovable poo.

As an added bonus, you will be leaving a pathway open for sewer gas to enter your trailer as there are no “p” traps on RV toilets.

Best practice is to have the black tank full (or nearly full) when you pull that handle to dump as gravity and water are your friends.

Also good to have enough water in the gray tank to flush the sewer hose when you are done.

[LEA777]

Thank you much. That makes sense . ��

[Dennis C]

You might consider a different tank treatment than what you’ve been using If tank odor is a problem. I found that tank pods and deodorizers aren’t very effective. Last year I switched to Happy Camper powder tank treatment, and it is much better than anything I’ve ever used. We have virtually no tank odors or problems.

[BigSxyWhtGuy]

Originally Posted by Dennis C

You might consider a different tank treatment than what you’ve been using If tank odor is a problem. I found that tank pods and deodorizers aren’t very effective. Last year I switched to Happy Camper powder tank treatment, and it is much better than anything I’ve ever used. We have virtually no tank odors or problems.

I’ll second the happy camper. We used the pods for one pack and switched to happy camper about 3 years ago. Haven’t used anything else since. We use the largest size to get best pricing but here is an affordable smaller option too.

https://www.amazon.com/gp/product/B0...36f532f4deaf7b

[Al and Missy]

I use TankTechs Rx. IT does a great job. No odors if directions followed.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[AppFan]

Happy camper is our go-to as well. 2.5 years and no odors.

I also use a 1/2 cup of dawn dish detergent and 1/2 cup of Calgon water softener after everything dump & flush.

[Fungus]

If I plan to drive to another site that has a dump station or sewer hookup, I leave some liquid in the tank to churn and dissolve the solids. Dump on the way in instead of on the way out. The black tank discharge looks almost like the gray after a hundred miles or so of sloshing.

[Hans627]

Another vote for Happy Camper!

[uraljohn]

I always drain black tank when at least 75% to 100% full. As it is draining I hook up my dedicated black tank flushing hose to the flush out port and turn on the water. Let it go couple of minutes. Close the blank tank drain valve and let tank refill with clean water to 75%. Open black tank drain valve and continue flushing until clean water comes out. Usually about 2 or 3 minutes. Close the blank tank drain valve and immediately turn off water. Nice clean tank ready to go again. Always keep black tank drain valve closed unless draining/flushing.

This has worked well for us for the past 4 years. We use the orange TST stuff from CW and no odor problems. I do lube the commode seal.

Nothing worse than the Black Mountain in the black tank.

[billsargent]

In addition to the "Happy Camper", which is the best IMO, I would suggest stocking some CALGON LIQUID water softener in your supplies and adding a capful at the some time as the Happy Camper. Not a large expense, and one that I trust.

[2MileHi]

Ahh, the dreaded Pyramid of Poop threat! Nice couple with three little ones spent two or three weeks next to us some years back. A day before they were to break camp they had what he described as a disgusting IED loaded with recent meals. It seems they had left their black tank valves open on two previous weekend camping trips in their new RV. It was pretty nice. I felt so sorry for them. They spent the rest of that day and all of the next cleaning it up and left nearly the middle of the night.

[Ol Bob]

Not previously mentioned is the fact many/most private CGs are run on a septic system. The perfect breeding ground for tiny flying "sewer bugs".
I see this all the time when I remove the sewer cap in preparation to stabbing my sewer hose & a host of them fly out. Yuck!
These obnoxious little creatures will fly up your dry sewer hose and take up residence in your black/gray tanks if the valve is in the always open position. Then when your partner flushes the toilet 🚻 they fly into your rig. Then they hide behind curtains. Get into tiny spaces. And reproduce ad-nauseum and are generally a nuisance and hard to get rid of.
Not a problem for the gray water tank since all it's drain sources have P traps preventing entry.
At the end the day I'm in agreement with all of the reasons mentioned by earlier posters but offer this additional cautionary warning ⚠️.

[Blazeman1]

We leave the tank open, and form a goose neck in the drain hose …