Full-time live-in: flush black at 2/3 or wait till full?

[justanotherrvr]

In our 33 foot, full-time live in Cherokee, we've had the black tank overflow at least twice. With the 33 foot Cherokee, there is no tight seal where the toilet drain enters the tank, just a rubber collar where the pipe enters, with no clamp or other mechanism to secure it. And so when the tank gets completely full, and the level rises above that collar, sewage water leaks out into the "basement" area between the floor and the bottom of the trailer, where the tank is. And there simply is no way to clean that area without many, many hours of labor, as you'd have to remove the cover that is bolted onto the frame, clean from underneath, and then re-seal the cover. Or pull out the toilet, tear up the bathroom floor, and clean from above.

I say that to avoid possible overflows, we should flush the black water tank the instant the sensor shows 3 out of 4 lights. Others here believe that flushing the tank before it reads completely full will cause the solids to build up and clog the tank. But with everyone here often very busy, it gets very close to overflowing way too often.

This isn't an academic or theoretical issue: twice when I've visually seen the sewage rise into the toilet pipe, there was brown water dripping from the bottom of the trailer, at the lowest point on the bottom, where the black tank pipe exits the bottom cover. And yes, the dripping water smelled exactly like the odors usually accompanying the black tank flushing process. The first time I called the dealership in a panic (it was still under warranty then), and they basically told me "yeah, that rubber collar just limits splashes and odors, if it rises into the drain pipe, sewage is going to leak out". Along with advising me the warranty doesn't cover such leaks.

I'm hoping to hear from others who have lived in a travel trailer full time, to learn how you all manage your own black water tank, and if any of you have had clogging problems by regularly flushing the tank at 2/3 full.

[Kimber45]

the sensors are close to worthless and highly undependable. I would go by days or step on the pedal and look down. Never would i risk the mess. If you dont travel and you are anual pull the tank and install a residential toliet.

You are never going to have a problem dumping early as long as you use plenty of water.

[Gmoney67]

First of all you need replace the gasket at the toilet and flange it should not leak there.When flushing my tank i got interrupted and had water flowing out vent pipe on roof that was the only place.I don't drain my black tank until mine starts burping when flushing.Its just 2 of us so about every 7 to 10 days drain and flush mine.Also the led lights are not anything to go by vary inaccurate.

[5picker]

During our winter stays in FL, I often drain the black tank at 2/3. As long as you use plenty of water at each toilet use involving solids or paper, the liquid ratio needed for dump flow will be fine at 2/3 or even half for that matter.

[justanotherrvr]

Originally Posted by 5picker

During our winter stays in FL, I often drain the black tank at 2/3. As long as you use plenty of water at each toilet use involving solids or paper, the liquid ratio needed for dump flow will be fine at 2/3 or even half for that matter.

Thanks; I've noticed that the first half of the flush is always all liquids, with the paper and solids following. So the theory that waiting for a full tank means the extra liquid will push out the solids is not confirmed by observing the process through the clear plastic coupling. It may not be scientific proof, but it works for me.

[NMWildcat]

I would revisit the problem of the leak where the pipe enters the tank. I've never seen an unsecured entry like that. I have seen a rubber section with clamps that I'm assuming is for flexibility, and I've seen glued pipe. Never seen one that allowed liquids out of the tank at the connection. Just doesn't seem right.
I would get a second opinion

[NXR]

Two thirds for me but we have a black tank flush that I use on most dumps. I have 52 gallon tanks. What size does your Cherokee have?

Many people add about 5 gallons of water after flushing to assure they have water inside when they start to use the tank again.

Ray

[rfifer]

We are not full-timers but commonly are out several days during vacation season. I will empty our black tank at 2/3 with no worries. But I also ensure that I have put RV chemicals in the tank to assist in the breakdown of solids. After I empty the tank, I'll immediately put chemical in and then add what I think is about 3-4 gallons of water to provide a liquid base. I just bought a cleaning tool (rotating sprayer) designed to clean the access pipe from the toilet to the tank and also the sensors. I have not had occasion to use it yet, but I am hopeful that will help with the sensors perhaps performing a little better. The other thing, with our 26 DBH we have a black tank flush. If there is concern about residual solids in the tank after emptying, a periodic flush does help. I don't know if your trailer has one or not. But if not, filling the tank with 10-15 gallons of water after you have emptied it and then empty it again should help to move out any residual solids.

[Fork in the road]

I would suggest using this tank treatment. It is supposed to liquify everything so you don’t have to worry about a clog no matter how full your tank is.

Unique RV Digest-It Black Holding Tank Treatment - Concentrated Liquid Toilet Treatment - Eliminates Odors, Breaks Down Waste (16 Treatments, 32 oz.) - 413-az https://www.amazon.com/dp/B07564FPHL...ing=UTF8&psc=1

[campers302]

Originally Posted by justanotherrvr

In our 33 foot, full-time live in Cherokee, we've had the black tank overflow at least twice. With the 33 foot Cherokee, there is no tight seal where the toilet drain enters the tank, just a rubber collar where the pipe enters, with no clamp or other mechanism to secure it. And so when the tank gets completely full, and the level rises above that collar, sewage water leaks out into the "basement" area between the floor and the bottom of the trailer, where the tank is. And there simply is no way to clean that area without many, many hours of labor, as you'd have to remove the cover that is bolted onto the frame, clean from underneath, and then re-seal the cover. Or pull out the toilet, tear up the bathroom floor, and clean from above.

I say that to avoid possible overflows, we should flush the black water tank the instant the sensor shows 3 out of 4 lights. Others here believe that flushing the tank before it reads completely full will cause the solids to build up and clog the tank. But with everyone here often very busy, it gets very close to overflowing way too often.

This isn't an academic or theoretical issue: twice when I've visually seen the sewage rise into the toilet pipe, there was brown water dripping from the bottom of the trailer, at the lowest point on the bottom, where the black tank pipe exits the bottom cover. And yes, the dripping water smelled exactly like the odors usually accompanying the black tank flushing process. The first time I called the dealership in a panic (it was still under warranty then), and they basically told me "yeah, that rubber collar just limits splashes and odors, if it rises into the drain pipe, sewage is going to leak out". Along with advising me the warranty doesn't cover such leaks.

I'm hoping to hear from others who have lived in a travel trailer full time, to learn how you all manage your own black water tank, and if any of you have had clogging problems by regularly flushing the tank at 2/3 full.

Open your drain and leave it open. Close on occasion to do a full rinse and flush and then open and leave open.



People are going to say you cant do that because of a pile that will develop and that is what the closing and full rinse will take care of.


Others will say that you will get sewer odors from having the line open and as long as you have a low spot in your line before it enters the sewer that will block sewer gas.



At least try this.


Good luck.

[NavyLCDR]

Originally Posted by Fork in the road

I would suggest using this tank treatment. It is supposed to liquify everything so you don’t have to worry about a clog no matter how full your tank is.

Unique RV Digest-It Black Holding Tank Treatment - Concentrated Liquid Toilet Treatment - Eliminates Odors, Breaks Down Waste (16 Treatments, 32 oz.) - 413-az https://www.amazon.com/dp/B07564FPHL...ing=UTF8&psc=1

And it's a good price too! Just don't expect this to work if you are going to keep the sewer valve open as suggested in the post above. Everything has to stay in the tank for numerous days for this to work. It's not acid, it's not going to work immediately.

[TitanMike]

Personally I hate leaks and would fix it even if it is an extensive project. Especially if living in it full time.


Otherwise just plan on dumping tank on a regular basis before it starts to leak.

[campers302]

Originally Posted by TitanMike

Personally I hate leaks and would fix it even if it is an extensive project. Especially if living in it full time.


Otherwise just plan on dumping tank on a regular basis before it starts to leak.

Well there you go. What TitanMike says it the absolute best fix.

[dahagen]

I spend 6 months of the year in my motorhome. I dump at about 2/3, or perhaps every 5 or 6 days. I use toilet chemicals each time after dumping. If you can see paper in the drain process, I suggest you change toilet paper. Find one that disolves easily.

[Volvodriver]

Full time living in our Sandpiper over eight years now and we've learned a thing or two about holding tanks and rv living in general. On holding tanks I believe the the number one rule is don't trust the sensors. Number two is see rule one. After years of traveling and then setting for a month or longer holding tanks, plumbing, and pipe joints and connections to all of them tend to weaken IMO.

We use to go 5,6 and sometimes into a 7th day before pulling the gate on the black and galley. The grey we would go maybe 10 days as there is only myself and the DW 95% of the time. About 6 months ago I started to see a leak come out of the underbelly coroplast that smelled like sewage when it was at 5 to 6 days full. Full disclosure, the coroplast has been opened several times and taped closed with FR 200 mph tape.

So when we were workcamping this past spring and summer in northern Iowa I got lucky and found an amazing rv tech who spent 30 years at an rv manufacturer and does select jobs for folks. He corrected the tank joints and sealed the connections and advised us since our rig is 8 years old now we should pull the tanks at 3 to 4 and MAYBE into a 5th day from now one. We do and no further probs. We were lucky to find him because alot of mobile techs won't do that type of job.

Dave

[TitanMike]

Originally Posted by Volvodriver

Full time living in our Sandpiper over eight years now and we've learned a thing or two about holding tanks and rv living in general. On holding tanks I believe the the number one rule is don't trust the sensors. Number two is see rule one. After years of traveling and then setting for a month or longer holding tanks, plumbing, and pipe joints and connections to all of them tend to weaken IMO.

We use to go 5,6 and sometimes into a 7th day before pulling the gate on the black and galley. The grey we would go maybe 10 days as there is only myself and the DW 95% of the time. About 6 months ago I started to see a leak come out of the underbelly coroplast that smelled like sewage when it was at 5 to 6 days full. Full disclosure, the coroplast has been opened several times and taped closed with FR 200 mph tape.

So when we were workcamping this past spring and summer in northern Iowa I got lucky and found an amazing rv tech who spent 30 years at an rv manufacturer and does select jobs for folks. He corrected the tank joints and sealed the connections and advised us since our rig is 8 years old now we should pull the tanks at 3 to 4 and MAYBE into a 5th day from now one. We do and no further probs. We were lucky to find him because alot of mobile techs won't do that type of job.

Dave

Can't blame those techs who refuse that kind of work. After all it is a CRAPPY JOB.

[jimmoore13]

You have many opinions. Here's mine.

There is no harm in dumping at 2/3. The goal is to have enough effluent in the tank to keep the solids somewhat emulsified and to facilitate dumping in a big whoosh. 2/3 full is plenty for that...especially considering the risk you face by allowing it to overflow (which, by the way, is a ridiculous assembly oversight!!).

Two suggestions.

1) In most cases, one can turn off the pump or city water, open the toilet flush valve, and use a flashlight to peer down the toilet to assess the status of the tank. I do this regularly when boondocking, because the lights on the control panel are unreliable.

2) When dumping, my practice is to have a "dirty" hose that I jet down the toilet to clean the bottom of the tank...especially any "pile" that builds up below the toilet flush. Use plenty of water to dislodge any solids, and this water will also help move along any stubborn solids that might be damming up the dump port. This is very effective. From there, if you have one, connect the dirty hose to your black tank flush, and this will help clean the sidewalls of the tank. You'll be surprised what gets dislodged and comes down the pipe.

I use a clear adapter about 6" long on the end of my dump pipe so I can monitor what's happening. I have a brass "Y" connector that I put on the city water connection so I can leave the city water hooked up and have the dirty hose connected simultaneously. The 1/4 turn ball valves on the Y connector let me shut off city water easily and shut off the supply to the dirty hose when it's not in use. I bought a 50' collapsible hose for the dirty hose. It's compact when not in use and easy to drain for travel. I keep it in its own separate bag for travel. I use Clorox cleanup on the city water hydrant, the Y connector, both ends of the potable water hose, and the connector end of the dirty hose....to keep things sanitary. One never knows whose dog has peed on your city water hydrant!

Best of luck.

[TitanMike]

When I was a kid on the farm we had one of these:



A yardstick "calibrated" to measure how much "stove oil" was in 55 gallon tank connected to the "heater/stove".

With all the concern about RV tank gauge's inaccuracy perhaps it's time to go "Old School" and carry a yardstick calibrated for the Black Tank

[PodGeek]

I always pour one or two 5-gallon buckets of water (maybe 2/3 full) down the commode while emptying the black tank.

That, coupled with a high water:yucky stuff ratio (as mentioned several times) has always done the trick. We also start out with maybe 3-5 gallons of water in the black tank before "using" it to keep things mobilized down there.

[GFD47]

This method is facilitated greatly by having a clear elbow connected between your outlet pipe and your stinky slinky.
If you have a black tank flush connection dump at 2/3 and rinse the tank using that. When the power flush water is m/l clear, close the emptying valve for about four or five minutes and let the water level rise in the black tank while the pressure flush hose is running. Then open the valve and more paper and solids will come out. I've pushed a cable-mounted TV camera probe into my black tank after doing this and it looked like brand new...nothing in it.
Actually, this method works at any tank level.