How to fully drain and clean the black tank

[Ronleague]

Hello everyone my question is how do you fully empty the black tank after going camping.
The camper was level at the camping site ball valves are open draining into the sewer line I flushed everything down several times using the gray tank last flush the toilet bowl several times before we left to clean the system out but when we got home I have pulled the black lever and still had about 10 gallons come out by accident how is that possible if everything was connected at the site and flushed down several times any help would be greatly appreciated

[Flybob]

Despite what you might think, the drain on any of the tanks installed in an RV is not always at the very lowest part of the tank. In addition the tanks are flexible and sometimes supports will distort the tank in a way to create several low points. What you are seeing is not uncommon.

[djousma]

There will always be "stuff" in the black/gray tanks. Just do your best to flush it every so often(I do this when on full hookups), but then don't worry about it. Many people get fixated on this, and have to have it "clean". My routine for the last 15 years, is to always re-prime the black tank after dumping. In other words, once dumped, close the black drain valve, dump the tank deodorizer in, along with 3 toilet bowls full of water, now you are ready to roll for the next trip. Never leave the tank dry, and it will give you good service for many years. Also, in case you are not aware, when on full hookup, its ok to leave your gray water tank valves open, but always leave your black closed until time to dump. Otherwise what will happen is the liquids will drain out, leaving the paper/solids, and eventually will fill the tank to the point where it will never drain, and becomes like concrete. That's a repair bill you don't want to have to pay!

Dave

[mustardbucket107]

I always try to leave 5-10gals in the black tank after dumping so going down the road it sloshes around

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[Restcure]

Originally Posted by djousma

There will always be "stuff" in the black/gray tanks. Just do your best to flush it every so often(I do this when on full hookups), but then don't worry about it. Many people get fixated on this, and have to have it "clean". My routine for the last 15 years, is to always re-prime the black tank after dumping. In other words, once dumped, close the black drain valve, dump the tank deodorizer in, along with 3 toilet bowls full of water, now you are ready to roll for the next trip. Never leave the tank dry, and it will give you good service for many years. Also, in case you are not aware, when on full hookup, its ok to leave your gray water tank valves open, but always leave your black closed until time to dump. Otherwise what will happen is the liquids will drain out, leaving the paper/solids, and eventually will fill the tank to the point where it will never drain, and becomes like concrete. That's a repair bill you don't want to have to pay!

Dave

Personal preference, of course, but on the few occasions when we camp with full hookups I leave all of the valves closed until the tanks are full. What gets washed down the sink into the grey water tank can smell just as bad as black water, so it's best to drain with as much liquid as possible to flush the solids out.

For the most part we drain at home with a Flojet.



After draining I flush the tanks. When flushing I rinse (black) or backfill through the Flojet (galley and grey) for 30 seconds before dumping again, repeating until the water is (relatively) clear.

[doc73]

I use a flush king after dumping to back fill the tank a bit. Even after a good drain I still get a bit extra out after I let everything settle for a while.

[325BH]

I honestly don't care and don't worry about it.

I dump. I flush. I refill with a couple of gallons of water and drop a tablet. Done.

Keep liquids in there and you won't have problems.




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[Kenny kustom]

Originally Posted by doc73

I use a flush king after dumping to back fill the tank a bit. Even after a good drain I still get a bit extra out after I let everything settle for a while.

I used the flush king this weekend for the first time.

I noticed that as well. Back fill, dump. Poop. Backfill dump, poop.


2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS

[doc73]

I've been happy with its usage and cleaning abilities... Just do not leave the tank alone if you close it up to backfill... If it fills and you are not there... Well it makes a nice brown geyser out the roof stack!

[Dogpatch]

I dump, use my black tank rinse and clear plastic elbow to view and then once clear water comes, pull the grey water. I run the taps in the sinks and then dump the grey again. Shut the gate valves. Add some "Happy Camper" run the water in the toilet and sinks for a minute and Alls good!

[Dr-G]

Originally Posted by doc73

...it makes a nice brown geyser out the roof stack!

Speaking from experience?

[doc73]

Oh yeah.. Old Poopful blew out the roof in Orlando... Never made that mistake again..

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[Dr-G]

Ugghhh!

[Restcure]

Originally Posted by doc73

Oh yeah.. Old Poopful blew out the roof in Orlando... Never made that mistake again..

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Ay caramba! DEFINITELY the kind of mistake you don't make twice.

[B and B]

Originally Posted by djousma

There will always be "stuff" in the black/gray tanks. Just do your best to flush it every so often(I do this when on full hookups), but then don't worry about it. Many people get fixated on this, and have to have it "clean". My routine for the last 15 years, is to always re-prime the black tank after dumping. In other words, once dumped, close the black drain valve, dump the tank deodorizer in, along with 3 toilet bowls full of water, now you are ready to roll for the next trip. Never leave the tank dry, and it will give you good service for many years.

Dave

X2 same thing, leave ready for next trip. We seldom use black flush as the Dump Station do not have hose fittings. 90% we camp with only electric. On top of this water is not plentiful and we should not waste it cleaning a black tank.

[doc73]

Originally Posted by Dr-G

Ugghhh!

Originally Posted by JD and Beastlet

Ay caramba! DEFINITELY the kind of mistake you don't make twice.

Luckily I had flushed the tanks several times prior so it was actually pretty clean water... As clean as a black tank COULD be!

[spock123]

Originally Posted by B and B

X2 same thing, leave ready for next trip. We seldom use black flush as the Dump Station do not have hose fittings. 90% we camp with only electric. On top of this water is not plentiful and we should not waste it cleaning a black tank.

I empty the black water tank and then close the valve and using the black tank flush about fill the tank again and empty and keep doing that until the water runs clear. I don't use my outdoor shower so that hose stays hooked up to the black water flush. I sometimes use hot water to wash out my black tank. Works for me


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[Hack113]

The biggest reason that holding tanks, on Forest River Camper, do not fully drain, is because they use "Flat-Bottom Tanks" instead of "Sloped-Bottom Tanks".
Our previous 5th wheel was a Keystone Copper Canyon, it had "Sloped-Bottom Tanks", and that camper would "almost" completely drain, when the camper was level.
Our current 5th wheel is a Forest River Cedar Creek Silverback, and has "Flat-Bottom Tanks". The bottom of the tanks "Bow Down" on the bottom, especially when filled with liquid.
When the camper is level, as when set-up at a campsite, the tank will never fully drain. There will be 2 - 3 gallons of liquid left in the tank. With the black tank, that means there will always be "poop" (smell) in the tank.
Our camper has the Lippert 6-point Level System. When we get ready to leave a campsite, the last thing I do is use the hydraulic system to raise the front landing gear, to 1.2 deg high in front, then raise the right side to 1.2 deg high on the right side.
I then do my normal back flushing. I use a Flush King & flush each tank until they run clear water.
There will be 2 - 3 gallons of liquid drain from each tank after the the camper has been tilted.
I just wish Forest River would use the "Sloped-Bottom Tanks" so they would fully drain when level.

[sewingcybermom]

Originally Posted by Dogpatch

I dump, use my black tank rinse and clear plastic elbow to view and then once clear water comes, pull the grey water. I run the taps in the sinks and then dump the grey again. Shut the gate valves. Add some "Happy Camper" run the water in the toilet and sinks for a minute and Alls good!

"Happy Camper" is the best on the market, IMHO. We never leave home without it.

[Mr. Dan]

We also use Happy Camper... have for 3-4 years.