# Grey And Black Tank Blues



## xr75 (May 29, 2008)

Howdy everyone. I have a question about why it takes SO LONG to drain my holding tanks. I have had an '03 26rs and now a '03 28bhs and both have the same issue. Water comes out better from the grey than the black, but both slow to a trickle not long after the valve is opened and seemingly never fully empty. That's not always a good thing when there are long lines at the dump station. Could poor drain placement in the tanks and the angle of them be a possible cause? Just weird to me that both campers acted exactly the same way. Any ideas?


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## willingtonpaul (Apr 16, 2010)

you could have some deposits in the tanks that have built up over time, and not getting complete empties in the past....

dump a half gallon of bleach in each tank, along with some water softener (like calgon powder) and then a cup or two of laundry detergent like tide or whatever.

then fill the tanks to 1/2 to 2/3rds full with warm to hot water, and take the trailer on a good jaunt, for like 45 mins or so. lots of turns and acceleration / deceleration to slosh things around in the tanks....

then dump.

the beach sanitizes, the soap suds up and cleans, and the water softener helps to leave the walls of the tanks slippery, like softened or conditioned water feels when it comes out of the tap....

this should help....and you might be surprised to see what comes out.....

and might need to do it a couple of times.....


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## xr75 (May 29, 2008)

Thanks for the reply. Will give it a try. Find it odd though that both are '03 and they act the exact same.


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## zrxfishing (Sep 12, 2007)

You can put a bag of ice in the blank tank just before you leave for your 45 min trip. It helps clean anything off the side of the tank & level sensors.


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## GlenninTexas (Aug 11, 2004)

2x on the ice, it'll scour the hard deposits as it sloshes around.
Also take a 2x6 or something like that and put it down on the oppisite side of your tank drain. drive up on it when you are at the dump station to give yourself a little better angle.

Regards, Glenn


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## CamperAndy (Aug 26, 2004)

The tanks have the drains located on the side of the tank and are poor drainers at best.


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## Oregon_Camper (Sep 13, 2004)

Considering you probably have a 4" pipe/hose. The volume of water (or lets just say liquids for now) would be as follows for a 10' drain hose

1 gallon = 231 cubic inches / 1 foot = 12 inches / 10 feet = (10 x 12) = 120 inches Radius = 2 inches

Volume = pi R[sup]2[/sup] H = pi x (2)[sup]2[/sup] x 120 = 480 pi cubic inches = (480 pi / 231) = *6.528* gallons (rounded)

So you have about 6.5 gallons for every 10' of hose...just think how fast the "liquid" is coming out when you first open the valve. It is not hard to then realize these 40 gallon tanks can empty very fast. Then you will be left with the dribbles at the end. I let it dribble for 15-20 seconds...then call it good.


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## willingtonpaul (Apr 16, 2010)

Oregon_Camper said:


> Considering you probably have a 4" pipe/hose. The volume of water (or lets just say liquids for now) would be as follows for a 10' drain hose
> 
> 1 gallon = 231 cubic inches / 1 foot = 12 inches / 10 feet = (10 x 12) = 120 inches Radius = 2 inches
> 
> ...


they said there would be no math on outbackers.com......


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## Jewellfamily (Sep 25, 2010)

I only let the water dribble for about 1 minute on mine on each gray tank and black tank. I always recharge the black tank with about 1-2 gallons of water and chemical while draining the other 2 gray tanks so the small amount of liquid left is diluted and freshened up with potty chem. You can always pour bleach down the gray tanks if they have any odor from not getting the small amount of remaining liquid out.


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## xr75 (May 29, 2008)

Thanks for all the tips. Will check back with results next time I use the camper.


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## smith (Aug 15, 2013)

I solely let the water dribble for regarding one minute on mine on every grey tank and black tank. I invariably recharge the black tank with regarding 1-2 gallons of water and chemical whereas debilitating the opposite two grey tanks that the bit of liquid left is diluted and freshened up with potty chem. you'll invariably pour bleach down the grey tanks if they need any odor from not obtaining the little quantity of remaining liquid out.You can use plastic pipe.


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## GlenninTexas (Aug 11, 2004)

Here's my recomendations.

The clear elbows are a good idea. You can see if the drainage is running clear and stop flushing.

After you have dumped, add a bag or two od crushed ice down the toilet. As you drive home, the ice will scrub the bottom of your tank and melt. Dump again on the way home or once you get home if you can to remove the scrubbed residue. You don't necessarily have to do this after every trip.

Once you've dumped, add 2-3 gallons of water and appropriate amount of chemical to the black tank. Add a gallon or so with chemical down the sinks for the grey tanks. You may also consider adding some calgon water softener to keep the residue from sticking in the black tank.

If you are flushing at home, use all the water you want, but if your flushing at a dump station at a campground remember to be consious of others waiting to dump. Running a flush for 20 minutes there might get you a butt kicking.

Oh and one more tip. Before removing the cap from your dump pipe, check to make sure the black tank handle is in the closed position and stand a little to the side.

Happy dumping, Glenn


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