Thread Tools Search this Thread Display Modes
Old 06-02-2013, 09:30 AM   #1
Winnebago Owner
osgoor's Avatar
Join Date: Jul 2012
Location: All over the place
Posts: 147
Black water tank on full hook hookup

We are still new to all the ins and outs of RV'ing and had this questions. when on full hookups, do you leave the tank handle out so all flows through or do you still leave it closed and drain before leaving? We currently only stay a few days at any place and then the RV goes back into storage for a week or more. I am concerned that with that little use, the solids will accumulate and become a problem.

How do people on weekend trips best handle this?

osgoor is offline   Reply With Quote
Old 06-02-2013, 09:41 AM   #2
Winnebago Owner
njs42's Avatar
Join Date: Apr 2011
Location: Federal Way, Wa.
Posts: 97
You can leave the grey tank open. The black tank closed. Dump the black tank when it gets above 3/4 so you have a full flush and some water accumulation to carry solids out. I like to rinse then by filling about half way with fresh water and dump twice for good measure. If you are set to leave and there is little accumulation then fill the tank with water and flush. Again I do this several times.

The key to black tank is to flush when full or there about and to use lots of water when you use the toilet.

I also use chemicals to clean as I go, lots of differing ideas about this so if you search the threads you can read the many differing opinions.

Both tanks can use a periodic cleaning, say at least once per year. Use either a commercial cleaner or a home brew (plenty written about in the threads).

My only claim to fame in all this is that after ten years of use my internal black tank sensors still work properly. It is a good indicator of proper black tank maintenance.
I do all my own stunts
03 Dolphin LX 6355, Workhorse W22, 8.1 vortec, 04 CR-V, Blue Ox, Brake Pro----Norm, Barb and
Doc(He's a PhD)
njs42 is offline   Reply With Quote
Old 06-02-2013, 10:14 AM   #3
Winnebago Master
FIRE UP's Avatar
Join Date: Dec 2009
Location: Out there, somewhere
Posts: 1,600
You can do as mentioned above and, it will work. RVers have different ideas on how they do certain tasks. What we do in "hook up" situations is, we keep the black and gray closed. We shower, do dishes, and all the normal stuff which, eventually will fill the gray water tank. Now, here's something I kind of developed on my own. Since we, like you, may only stay in one place for short times, (1-4 days plus or minus) when we flush the toilet after business, I fill it to almost capacity. Then, flush. That puts a larger amount of water in the black tank when it comes to dumping it. And, more importantly, it helps prevent the build up of solids, directly below the flush valve. In other words, it "Spreads the load out" so to speak.

Now, if and when the gray tank gets near capacity, and, it may or may not be near the time for departure, I'll dump the black tank which, by adding more water for each flush, does a much more thorough emptying of the that tank. Then, by having a fuller gray water tank and then emptying that one, it has a higher volume of flow for carrying away waste(solids) that may be lodged in the hose from dumping the black tank.

You can still rinse either tank which, is a good practice in and of itself but, less water may be needed due to the fact that both tanks had high volume in the first place and when it came time to empty them, they both had high volume/fast flow characteristics during the empty process. Hope this helps some.
2004 ITASCA HORIZON 36GD, 2011 GMC Sierra 1500 4x4 Toad '08 GL 1800 Gold Wing
Retired-29.5 yrs, SDFD, Ham - KI6OND
Me, Karla and the Sophie character, (mini Schnauzer)
FIRE UP is offline   Reply With Quote
Old 06-02-2013, 10:29 AM   #4
Winnebago Owner
dennis45's Avatar
Join Date: Jun 2012
Location: BC
Posts: 77
Here is a site with a few "RV How To" Videos that might be helpful.
Dennis & Carol
2003, 4006, 41' DutchStar, [SIGPIC][/SIGPIC] Spartan, ISC 8.3L W/BanksPower - 2013 Honda CRV, BlueOx Baseplate, Aventa Bar & Patriot Brake. And the 04 Bird, Sunshine Car.
dennis45 is offline   Reply With Quote
Old 06-02-2013, 10:50 AM   #5
Winnebago Owner
vsheetz's Avatar
Join Date: Jun 2012
Location: SoCal
Posts: 227
I keep both grey and black closed while camping - dumping as needed if extended stay.

When leaving dump the black, next rinse the black for a few minutes while I put away other things, then dump the gray to flush the hose, lastly add chemical and a few gallons of water to the black tank.
Vince and Susan
2011 Tiffin Phaeton 40QTH (Cummins ISC/Freightliner)
Flat towing a modified 2005 Jeep (Rubicon Wrangler)
Previously a 2002 Fleetwood Pace Arrow 37A and a 1995 Safari Trek 2830.
vsheetz is offline   Reply With Quote
Old 06-02-2013, 11:43 AM   #6
Registered User
Join Date: May 2007
Posts: 301
As Scott mentioned, everybody seems to have different ideas on how to manage their tanks. You'll get all kinds of different procedures pertaining to using chemicals, not using chemicals, procedures to clean the tanks, etc., etc.

As others have mentioned, things I think we all agree are 1) never leave the blank tank valve open or, and the most polite way to put it is, you'll definitely acquire the dreaded "pyramid of poop" ...we can explain it further or you can imagine how it is acquired and how difficult it is to get rid of, and 2) always dump your black tank before dumping your grey in order to make it easier to keep your hose clean and as sanitary as possible.

Otherwise, I think in time, you too will formulate your own method on how you want to manage your waste tanks by trial and error and from advice from others.

Good luck!

amanda_h is offline   Reply With Quote
Old 06-02-2013, 02:15 PM   #7
Registered User
glenda1908's Avatar
Join Date: Jun 2004
Location: Virginia Beach, VA
Posts: 396
We used to keep both closed while hooked up for any length of time. But friends of ours who are full timers said it is fine to leave your grey tank open. Esp. if you are doing a lot of laundry, showering and kitchen sink tasks. It keeps from having to run out and empty the grey tank late at night or early in the morning when you realize it's full and you are getting ready to shower However, if we are nearing full on the black tank I do close off the grey so shower and laundry water accumulates. Then I have that water to flush out the hose after I empty the black tank. This has worked well for us. NEVER leave the black open though. Gas will come into the coach from the bowl
glenda1908 is offline   Reply With Quote
Old 06-04-2013, 01:26 AM   #8
Winnebago Master
DAN L's Avatar
Join Date: Sep 2007
Posts: 722
in addition to leaving the black tank closed and dumping it when it is nearly full, i fill my gray tank to at least 2/3 prior to dumping black tank and flushing it.
then i add 2 cups of bleach to the gray tank and dump it to flush out the stinky slinky so it is not so stinky.
01 WINNEBAGO 35U W20.8.1L SW Wa, Hi. Good Sam, SKP. AMSOIL fluids. BANKS ecm program. SCAN GAUGE II w/ Ally temp. 2 LIFELINE GPL-6CT AGM Batts on their sides. TST tptts. K&N panel air filter. AERO mufflers. TAYLOR plug wires. ULTRA POWER track bar. KONI fsd shocks, toad '14 smart car
DAN L is offline   Reply With Quote
Old 06-04-2013, 04:59 AM   #9
Winnebago Camper
Wolfpack Fan's Avatar
Join Date: Dec 2010
Location: Reno, Nevada
Posts: 5
Lot's of great suggestions. I'll throw in my technique. We like many others leave the gray valve closed most of the time. After a few showers I'll dump it off a little. No scientific method to it, I just make sure there's enough space for more showers and kitchen tasks. The black stays full for the duration of our trips, most of which are 2 to 4 nights. The morning we start break down for heading home I open the black tank and wedge a toilet bowl brush on the flush pedal of the toilet. Break down of camp will take around 40 minutes, all the while fresh water has been flowing into the black tank through the toilet. Once break down is complete I'll take the brush off of the toilet, close the black valve and do a final full dump of the gray tank. Last step is to fill the toilet bowl to the rim 2 times and drop in a chemical tablet. It leaves a few gallons of water to slosh around, with a higher concentration of the chemical in it as we head home. That little bit of water stays in it till next time we go camping.

My black tank sensor hasn't worked for some time and no amount of different types of flushes has resolved it. I think it's another issue. I can say though that odor control while camping is good with the technique I use now. It used to be that the smell of the tank would come up from the toilet bowl when you'd press on the foot valve. It's barely even noticeable now. Unless of course you're putting your face down next to the bowl. And who would wanna do something like that.
Harley Ultra Classic (Geezer Glide) Rider, Retired US Army Paratrooper, fisherman, shooter. Proud to have served, proud of those that still do, or have done so with pride.
2005 National Dolphin 34'
Wolfpack Fan is offline   Reply With Quote
Old 06-04-2013, 05:28 AM   #10
Winnebago Owner
HD4Mark's Avatar
Join Date: Oct 2009
Location: Marathon, Florida
Posts: 222
We do about the same dance with the tanks as others. The black tank can easily go a week so we leave the gray open until a day or two before dumping it, close it and take showers, run the dishwasher or whatever.

One CG we stay at that has a honey wagon instead of sewer connection on each site will pump the black, shut off the pump then open both so the gray will wash back up into the black tank for a quick rinse. I thought about trying that with a sewer connection but figure the slinky is big enough so that not much would back up into the black tank.

An unpleasant task we have to deal with.
Mark & Nancy
2004 Winnebago Vectra 40KD
Shep dog, R.I.P. Kenzie dog Toad 2015 Jeep Wrangler Willys Wheeler
HD4Mark is offline   Reply With Quote
Old 06-04-2013, 07:15 AM   #11
GG1's Avatar
Join Date: Aug 2002
Posts: 465
Usually we can go up to 2 weeks on our black tank but we find its best to dump once a week when on a sewer hookup. I use a clear fitting on my dump valve, dump then close the valve and fill the black tank through the flush fitting several times or more until the water runs clear. Sometimes I do this this for 30 minutes or more as long as it takes for the water to run clear. Our problem is the gray tank, my wife does a lot of cooking and a varity of waste oils go down the drain this is unavoidable, we find that the gray water tank sensor reads full all the time after about 2 months on the road. I have been using a product made by Roebic Industries for drains and holding tanks which works pretty good but after a few months the gray tank still gets residue on the inner wall causing the sensors to malfunction. Once we are home after 4-5 months on the road I use a flexible hose that swirls around on the end and insert it up into the dump valve of the gray tank and rinse over and over this finally get the junk off the walls and thegray sensor works again.
07 Itasca Ellipse 40fd, 2014 Honda CRV, greyhound lab mix, pit pointer mix(RIP bessie) , shar pei mix, stupid cat, wife
GG1 is offline   Reply With Quote
Old 06-04-2013, 07:29 AM   #12
Registered User
Join Date: Oct 2009
Location: Varies Depending on The Weather
Posts: 196
I treat both tanks the same way. I keep them both closed until full and then dump the black first, turn on the black tank flush, once that tank is empty, I pull the gray tank valve. Shortly before the gray tank is empty, I turn off the black tank flush, close the black tank valve which has been lubricated with soapy water from the gray tank and finally close the gray tank valve.

I've been using that method for 10 years while full-time living in my coach and never have any problems.

Without the "whoosh factor" your tanks do not get as clean. By leaving the gray tank open, I can guarantee that you will have a waste buildup on the bottom of your tank of food particles, grease, oil, etc. The "whoosh factor" prevents that from happening.

Dr4Film ----- Richard
Dr4Film is offline   Reply With Quote

tank, water

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
HOW TO HOOK 100 lb propane tank to Motorhome Kenvb General Maintenance and Repair 31 12-25-2016 09:07 AM
Full wall slide will not full retract corjaguar General Maintenance and Repair 27 04-05-2014 02:51 AM
Shower water going into black water tank Wxman1 Plumbing | Systems and Fixtures 10 11-06-2011 07:09 PM
Black Tank Sensor shows Empty - even when full! DavidLyle Plumbing | Systems and Fixtures 8 02-17-2010 02:38 PM
Potential Full Black Water Tank Problem vicsryd Plumbing | Systems and Fixtures 15 05-15-2006 02:34 AM

» Featured Campgrounds

Reviews provided by


This website is not affiliated with or endorsed by Winnebago Industries or any of its affiliates. This is an independent, unofficial site.

All times are GMT -6. The time now is 12:21 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.