How full is full? (Black tank)

[boubou64]

Been parked for 9 days at a CG with no sewer on site. We've been careful to go to the toilets on the CG most if the times except nights and early morning. Of course, the sensor showed 3/4 full after two days so we knew not to trust it too much from there but I think the waste have caught up to the sensor by now.
Question is: once the sensor shows full, how much room is there still? ( kinda like how far can we drive on Empty).
We still have 5 days before going home and would rather not have to go dump until ready to go.
Also, what happens if we keep using when the sensors mark full if we can't see anything in the tank through the toilet hole?
I should add that the black tank is 37 gallons and there are two of us in the trailer.

[12thgenusa]

boubou64 wrote:
I guess my concern was for spillage on our way to the dump site if too full.

It is a fully enclosed tank. Nothing will spill.

[rockhillmanor]

Also, what happens if we keep using when the sensors mark full if we can't see anything in the tank through the toilet hole?

That means you've got a ways to go! :B
Seriously if you don't see it coming up to the top there is still room in there for you to keep using it.

Is your RV perfectly level? If not it does affect your gauge. I found out the hard way. The gauges are usually on one side of the tank so if you are tipped the opposite way even just a little it will show less than what is in there.

IMHO when boondocking Using a flashlight is really the only TRUE way to find out!

[paulcardoza]

The "burp" method gives you the best indication that the tank is really full. Just note that when it burps, you need to stop using it as it is REALLY full. It'll definitely be time to dump.

[boubou64]

midnightsadie wrote:
is there septic tank pump out available at the park.

No, we asked 😞

[beemerphile1]

Once it starts burping air when flushing I know we are nearly full. I need to flush within a day.

[TucsonJim]

If going this many days is going to be a frequent occurrence for you, you might want to invest in a portable dump tank so you don't have to break camp to dump.

[Cloud_Dancer]

When in doubt,...dump.

There's just two of us, and our MH has 50 gallon black tank. The longest we go is 6 days, then we make sure we go dump.
BTW all of our guages/indicators work (fairly accurate too).

[midnightsadie]

is there septic tank pump out available at the park.

[boubou64]

We've used it mostly for urine and threw toilet paper in trash to save space.
We do have a black flush and will use it.
I guess my concern was for spillage on our way to the dump site if too full.

[2edgesword]

You should start seeing "stuff" through the hole in the toilet when the tank is full.

One thing I was told when going through my initial inspection was to avoid using too LITTLE water when flushing. You don't want the black tank packed tight with solid material but rather more liquid then solid. A higher concentratiion of liquid versus solid will help move the solid stuff out of the tank when dumping. This is probably more important if you don't have a black tank spray installed to rinse the tank after dumping.

I was also advised that after dumping to put a couple of gallons of water into the tank with a packet of black tank treatment to prevent any remaining stuff from solidifying.

[Vet_Man]

Sound is a good way for me to tell. It sounds different when you flush and it is near full

[rk911]

you can open the lid on the john and using a flashlight see where the level is. if you can see water then it's time to dump. but we've taken all of the stress out of this. experience has taught us that we (there's just two of us) can use the facilities in the MH for a week without *having* to dump. so I just dump the tank once a week or when we leave the park/CG, whichever comes first.

[byways]

You will know when it is full! It may burp some air when flushing. Or, you will see the...ummm...stuff through the black hole. Forget about the sensors.