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Author Topic: Grey water holding tank #2  (Read 331 times)


  • Posts: 1
Grey water holding tank #2
« on: August 25, 2017, 08:05:15 AM »
I was wondering how do you activate the #2 grey water tank is it an overflow? It never seems to fill up unlike tank #1


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  • Posts: 6395
Re: Grey water holding tank #2
« Reply #1 on: August 25, 2017, 08:18:45 AM »

It is not likely to be an overflow in the normal sense. Those trailers/motor homes with a second grey tank usually have it connected to the bathroom sink, the shower or both. The first tank is usually connected to the kitchen alone in these cases. Some may have the bathroom sink connected to the black tank when a second grey has not been provided.

Hopefully you found a shut of valve for that second tank and have not left it open so it drains all the time. Nothing wrong with that if you are aware of it and hooked up but.... it's best to know. BTW, NEVER run with the black tank open all the time, hooked up or not or you will likely create problems you would rather not have!!! (Look up poop pyramids).
« Last Edit: August 25, 2017, 08:27:54 AM by Alfa38User »
Montréal, Canada 🍁
Snowbird, Naples Florida
Alfa Gold 38 (2000) 5ver (parked!)

"Of course I talk to myself, sometimes I need expert advise!!!"


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  • Posts: 1920
Re: Grey water holding tank #2
« Reply #2 on: August 25, 2017, 08:30:09 AM »
X2 what Stu said - that's how mine is plumbed. The 2nd grey tank (the galley/kitchen in my case) has a separate discharge pipe and knife blade to open. It was located about 3' behind the main sewer pipe in an inconvenient place under the slide so I added about 3' of pipe and now the two outlets are right next to each other. There have been a few recent discussions here about hard-to-find pipes or knife blades - you may have to search around under the rig to find yours.
Joe & Kim
Upstate NY - Kuyahoora Valley
2010 GMC Sierra 2500HD - 6.0L
2017 Keystone Hideout 295BHS
Andersen Ultimate Aluminum 5th wheel hitch