RV Trip Planning Discussions

Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
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 08-18-2018, 10:53 AM   #1
Junior Member
Join Date: Jul 2018
Posts: 5
Sani problem

Bit of a story here, we have bought a 2010 serrano Thor motor home. Very little miles 17thousand. Found out some history people used it to live in while caretaking a campground. First trip out black tank filled really fast, we figured maybe dealer had not emptied before we got it. Second trip same thing, we have now figured out they must have been hooked to sewer and kept the valve open so we have stuff built up in tank. Am wondering if anyone has any home remidies for putting stuff in tank to help break down crap? I have been flushing it out with hose attached wand cleaner from top and think I am making some headway. Just checking to see if anyone has any other ideas.

Ladydi45 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 08-18-2018, 11:11 AM   #2
Senior Member
Lt Dan's Avatar

Tiffin Owners Club
Join Date: Sep 2013
Location: DFW, Texas
Posts: 2,800
The best thing is to fill it at least 1/2 full of water with a little Dawn dish soap and let it soak for a couple of weeks. Your'e going to have to soften the poo pyramid before you can wash it out. You may have to rinse-repeat several times to get it all.

Here's another thread about a similar problem:
Black Tank Sludge Treatment ???

Dan & Ro with two Rescued Boston "Terrorists" Jade & Jewel
2017 Phaeton 40IH Maroon Coral - Power Glide Chassis with IFS (05/17)
Previously '15 Tiffin Allegro RED 38QRA and '06 Itasca Sunrise 35A
'12 Jeep JK Wrangler Sport or '08 Honda Goldwing
Lt Dan is online now   Reply With Quote
Old 08-18-2018, 12:03 PM   #3
Senior Member
Join Date: Nov 2017
Location: Citra, Florida
Posts: 1,300
Originally Posted by Lt Dan View Post
The best thing is to fill it at least 1/2 full of water with a little Dawn dish soap and let it soak for a couple of weeks. Your'e going to have to soften the poo pyramid before you can wash it out. You may have to rinse-repeat several times to get it all.

Here's another thread about a similar problem:
Black Tank Sludge Treatment ???
X 2 Does the rig have a tank flush on the black tank? Leaving that on with the valve open will eventually get some of it out after the Dawn attack.

A wand that can be stuck into the tank from the toilet or from the valve in the wet bay might be of some use also, the kind that takes a hose on one end and creates a penetrating spray
Good Luck and keep us posted please. "Q"
1999 Newmar, Mountain Aire 3768, V-10, CAI, Headers.
"Spending our kids inheritance one trip at a time"
Quincy is offline   Reply With Quote
Old 08-18-2018, 12:28 PM   #4
Senior Member
Dennis_K's Avatar
Monaco Owners Club
Join Date: Jun 2007
Location: Lake Havasu City, AZ
Posts: 1,279
You could try "Commando Black Holding Tank Cleaner".
2012 Monaco Knight 36 PFT
2019 Jeep Grand Cherokee Overland
2005 Jeep Rubicon Unlimited on 2007 16' Car Hauler trailer.
Dennis_K is offline   Reply With Quote
Old 08-19-2018, 12:24 AM   #5
Senior Member
ThePowells's Avatar

Join Date: Mar 2017
Location: Zebulon, NC
Posts: 4,309
Welcome to the forum!

Here is a link to about 250 threads that have previously dealt with your issue.

The first thread in the list is a presently active one.

Kelly and Jerry Powell with Halo (Lethal White Aussie), Nash the Rat Terrorist, and now Reid, the "Brindle we have no idea puppy"
2017 Thor Quantum W31, Ford E-450, Onan QG4000, Demco Kar Kaddy, Toytoada Prius.
ThePowells is offline   Reply With Quote
Old 08-19-2018, 12:55 AM   #6
Senior Member
saddlesore's Avatar

Foretravel Owners Club
Join Date: Apr 2016
Location: Salem,Orygun
Posts: 3,697
Add a cup or so of Calgon liquid with your Dawn soap, and let it mellow for a few days, hitting it with the wand every day or so...then ..after a few days try to dump the tank combined with the pressure wand..
good luck.
Foretravel with tag axle.
retired truckdriver with 5m miles
Orygun Native
saddlesore is online now   Reply With Quote
Old 08-19-2018, 02:54 AM   #7
Senior Member
SuperGewl's Avatar
Winnebago Owners Club
Ford Super Duty Owner
Join Date: Aug 2004
Location: Oregon
Posts: 2,102
Everything said so far is great and right on point. Next trip after you break camp make sure to add that water/bath salts/dawn mixture and dump the Ice tray into the crapper also. If you don't have an ice tray then get a 5 lb bag of ice and dump it in there. The ice will help beat up the crap while traveling then dump it upon next camp ground or end of trip.
The only other thing would be the dreaded high pressure back flush or top down flush if the toilet sits right on top of the tank. But you need a pressure washer and have to be hooked up to water and sewer for this. The back flush is the nasty one so be prepared to get crappy

OK just fill it and soak it, fill rinse repeat. It may take a couple of weeks, but keep water in it.
Retired Navy Submariner
2014 Itasca Sunstar 35F; 5 Star tuned; 2014 Jeep Cherokee TrailHawk
SuperGewl is offline   Reply With Quote
Old 08-19-2018, 03:47 AM   #8
Senior Member
Arch Hoagland's Avatar
Monaco Owners Club
Workhorse Chassis Owner
Join Date: Aug 2002
Location: Clovis, CA, USA
Posts: 7,587
Use a regular whole bottle of Dawn dish soap mixed with water in the bowl of the toilet so it's dissolved in the water before you flush it down.

Then fill the black tank completely full and let it sit for a couple days.

I use a cup mixed that way after every trip in both my black tanks and haven't had a problem for the past 13 years.

I also use that solution to scrub the seals with a three inch toilet brush in both my toilets and then keep water in the bowl while stored so they don't dry out.

I haven't had a problem with the seals in the toilets for 13 years using that technique.

2004 Monaco La Palma 36DBD, W22, 8.1, 7.1 MPG
2000 LEXUS RX300 FWD 22MPG 4020 LBS

Don't know where I'm going, spose I'll get there anyway.
Arch Hoagland 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
RV Sani Con - hose smell Globetrotter Monaco Owner's Forum 17 09-30-2017 03:50 PM
RV Sani con units Globetrotter Newmar Owner's Forum 24 10-17-2007 09:00 AM
Sani-Con/Grey Water Transfer Questions JavaJelly MH-General Discussions & Problems 6 04-05-2007 10:31 AM
sani con system? worth it? uncle t MH-General Discussions & Problems 5 09-21-2005 08:11 AM
RV Sani-Con Sewage System Gadget Man MH-General Discussions & Problems 7 06-21-2005 08:24 AM

» Featured Campgrounds

Reviews provided by

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 02:52 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.