Go Back   iRV2 Forums > TRAVEL TRAILER, 5th WHEEL & TRUCK CAMPER FORUMS > Travel Trailer Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 05-06-2013, 11:03 PM   #1
Senior Member
gazingm42's Avatar
Join Date: Jan 2003
Posts: 297
Gray and Black Tank questions

OK a newbie here when it comes to Gray and Black holding tanks. Just
picked up a new trailers and have not had our shake down trip yet.

So listening to my dealer and reading online I get a few different opinions.

So from what I am reading .....

When camping at a full hook sites.

Keep your black and gray tanks closed. Then as they become 2/3 full you
empty the black tank first. Then using a wand you can clean your black tank some more with several flushes.

Next empty the gray tank, which should have been closed. Keeping it open you can use your sink to run some clear water.

Once both are empty shut the values off and put the treatments in the black tank again.

Have I miss understand anything on the care of these. Please let me know how to care for these tanks.


TT: Dutchmen 2014 261BHS
TV: Ram 3500 6.4 HEMI, 3.73 6ft bed 2014.
gazingm42 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 05-06-2013, 11:07 PM   #2
Senior Member
Mr_D's Avatar
Winnebago Owners Club
Solo Rvers Club
iRV2 No Limits Club
Join Date: May 2011
Location: Vancouver, WA
Posts: 31,279
Pretty much correct except the tank flush. We have a built in flushing system and I've only used it a couple times in 12 years and never had a problem with any build up.

2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '14 CR-V
Mr_D is offline   Reply With Quote
Old 05-06-2013, 11:19 PM   #3
Senior Member
no3putt's Avatar
Join Date: Apr 2012
Location: Pueblo, CO
Posts: 533
Look up Geo-method much cheeper than buying products from rv centers. Uses calgon and liquid soap. We have used this method for 2 years and no smell etc. Also you gauges will not be all that accurate but you will figure out how long between dumps in no time
no3putt is offline   Reply With Quote
Old 05-06-2013, 11:30 PM   #4
Senior Member
RVluvin's Avatar
Join Date: Mar 2011
Location: Wittmann, AZ
Posts: 256
Do a search for the GEO Method, I've been happy with the results. I like using a clear plastic extender that attaches between the clean out and the stinky slinky, this way you can see when you've have rinsed enough water through the tanks. Even though I have the tank flushing system, I still like to use the wand down the toilet on my final rinse before going back into storage. Lastly, keep some hand soap near by to use when your done. Have fun!!
RVluvin is offline   Reply With Quote
Old 05-07-2013, 09:04 AM   #5
Senior Member
tuffr2's Avatar
Join Date: Sep 2012
Location: Palm Coast Florida
Posts: 3,280
The black tank dictates everything. What is more realistic is the gray tank fills up many more times than the black tank.

When getting ready to dump the black tank I will take an extra long shower to make sure gray tank has plenty of water if needed.

I wait until black tank shows full. Why dump early when staying at full hook-ups?
I open gray tank 1st for a few seconds. This wets the sewer hose. Then open the black tank until empty. I leave the black tank open while I use the black tank flush for 1 or 2 minutes. (This is where you would use the wand). Then close the black tank. Add 3 or 4 gallons of water and then add chemicals. Then open the gray tank to clean the hose.

I use the black tank flush since it is easy to use. I think it helps keep the tank sensors working better.
tuffr2 is online now   Reply With Quote
Old 05-08-2013, 06:47 AM   #6
Moderator Emeritus
SmokeyWren's Avatar

Join Date: Jun 2011
Location: Midland County, Texas
Posts: 3,584
Originally Posted by gazingm42 View Post
When camping at a full hook sites.

Keep your black and gray tanks closed. Then as they become 2/3 full you
empty the black tank first. Then using a wand you can clean your black tank some more with several flushes.
No need to flush the black tank with a wand every time you dump. It won't hurt anything, but it's time consuming and not necessary. When on trips of less than two weeks, we never use the wand until we get back home and prepare the RV for storage.

When dumping the holding tanks at campgrounds, after the black tank is empty, we run a gallon or so of water through the pottie to wash out any remaining solids in the bottom of the tank. Then we drain the grey water tank to flush out the hose. Then close the drain valves and flush the pottie for 15 seconds or so to get some fresh water into the black tank, then add the de-stinkum.
Grumpy ole man with over 50 years towing experience. Now my heaviest trailer is a 7,000-pound enclosed cargo trailer, RV is a 5,600 pound Skyline Nomad Joey 196S, and my tow vehicle is a 2012 F-150 3.5L EcoBoost SuperCrew.
SmokeyWren is offline   Reply With Quote
Old 05-08-2013, 08:40 AM   #7
Senior Member
Join Date: Mar 2013
Location: Langley. BC, Canada
Posts: 677
I like using our Valterra 45 degree clear flushing elbow. Let's you back-flush into the tank. I back-flush maybe 5 - 7 times before it clears up. The clear elbow is nice because you can see if there is any more solids and tp coming out. And on the gray tank you can see when the tank has stopped flowing.

We bought the flushing wand and used it once. Too much of a bother. We also have the built-in flush setup but have not used it. The GEO method has rave reviews but we have not tried it. There's the bag of ice trick on the way home to help clear the black tank. Tried it once but did not seem to work. Don't skimp on using water before and after sitting on the john and dropping your solids into the tank, you need lots of water to move the solids out of the tank and through the hose.

We installed Horst probes on our black tank on our last TT and they sure worked great (no more false readings). Bought a set for our new TT but we have an enclosed underbelly and I can't figure out how to get in there without major surgery.
Gil & Deb & Dougal the Springer Spaniel
2014 KZ Spree 262RKS & Ford F250 supercab V10 4x4 LB
Langley, B.C.
myredracer is offline   Reply With Quote
Old 05-08-2013, 08:52 AM   #8
Moderator Emeritus
RickO's Avatar

Join Date: Jan 2007
Location: Litchfield Park, Arizona
Posts: 10,530
I think you've got the basics down but you'll develop your own preferences as you gain experience and learn how to do things in a manner which works best for you.

A couple of thoughts though:

*Do check out the Geo Method. You really don't need to be adding black tank chemicals at all if your tank is properly maintained.

*As mentioned, your grey tank will fill far more rapidly than your black tank so you'll often times be dumping only the grey tank.

*I try to never have both the black and grey tank valves open at the same time to avoid black water getting into the grey tank. Probably no rational explanation for doing this, but I'm kind of weird about that stuff.

*As mentioned, add some amount of fresh water to your black tank after dumping. I want to always have some liquid in there to help suspend the solids.

*Buy a good pair of rubber gloves to keep in your plumbing bay and wear them when handling the tank dumping duties. A bottle of hand sanitizer is a good idea too.

*When stowing your slinky hose, disconnect from the rig first and elevate the hose in order to drain all the liquids possible into the CG drain before disconnecting the hose. I like the slinkys which have caps to put on both ends for storage. Doesn't allow hose water to bleed out into the bay while traveling.

Best of luck.

Rick, Nancy, Peanut & Lola our Westie Dogs & Bailey the Sheltie.

2007 Itasca Ellipse 40FD
RickO is offline   Reply With Quote
Old 05-08-2013, 12:37 PM   #9
Senior Member
Selah's Avatar
Join Date: Oct 2012
Location: Indiana
Posts: 2,326
I flush my black tank every time I dump. I have a tank flush connection and use a seperate hose so it just doesn't take that much time or effort.
Your sequence is correct, black tank first, flush if you want, then the grey. If you have full hook ups and will be at one location for an extended period you may leave the grey tank open, then close it a few days before leaving so you have about 2/3 tank. You always wand to use grey to help clean out the sewer hose.

Paul, Kathy, and Tux the Mini Schnauzer
2014 Tiffin Phaeton 42 LH, 2013 Honda CRV
"When the time comes to look back, make sure you'll like what you see"
Selah is offline   Reply With Quote


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

» Featured Campgrounds

Reviews provided by

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:10 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.