Grey water tank - leave open while camping?

[THenne1713]

While many leave Gray open, (maybe best if you have big Class-A w/ Washing machine?), I prefer to close/ monitor use, and dump Black when GRAY fills and then FLUSH w/ GRAY. I would PREFER to NOT have a 1/2-3/4 full Black and empty/ Low Gray? LIFE changes results UNexpectantly

[SmilingSam]

I have always left it open to dump BUT always put either a couple sharp S bends in the hose OR a gooseneck vertical bend much like in domestic toilets - to keep the stink where it belongs and NOT in your mh !


GL

[JohnBike]

Just returned from a four-day trip. As recommended by the “experts” (you can tell they’re experts because they say so on YouTube), I leave both tanks closed, even if I have the dump hose connected to a sewer.
I was reminded of this good advice yesterday when I dumped the tanks before departure. As usual I started with the black tank. I noticed that the effluent was a bit on the clear side. After the black stopped flowing, I closed the main dump valve and opened the grey tank valve to backflush into the black. Then I closed the grey and opened the black. This time the black tank yielded some solid stuff. Had I parked with the grey tank open, I would not have been able to flush the black tank. The solid stuff would still be there.
Yes, I use the tank treatment that should break up the solid stuff, but it takes time to work. Having the contents of the grey tank available to rinse the black tank means a lot less worry about black tank buildup.
The black tank level indicator (old-fashioned lights) showed a 2/3-full tank for the last three trips despite the empty-flush-empty routine. This time, I finished with all lights dark, so the backflush from the grey is working to keep the level sensors clear as well as improve the emptying of the black.
Those YouTubers might be onto something.

[LETMGROW]

Originally Posted by JohnBike

Just returned from a four-day trip. As recommended by the “experts” (you can tell they’re experts because they say so on YouTube), I leave both tanks closed, even if I have the dump hose connected to a sewer.
I was reminded of this good advice yesterday when I dumped the tanks before departure. As usual I started with the black tank. I noticed that the effluent was a bit on the clear side. After the black stopped flowing, I closed the main dump valve and opened the grey tank valve to backflush into the black. Then I closed the grey and opened the black. This time the black tank yielded some solid stuff. Had I parked with the grey tank open, I would not have been able to flush the black tank. The solid stuff would still be there.
Yes, I use the tank treatment that should break up the solid stuff, but it takes time to work. Having the contents of the grey tank available to rinse the black tank means a lot less worry about black tank buildup.
The black tank level indicator (old-fashioned lights) showed a 2/3-full tank for the last three trips despite the empty-flush-empty routine. This time, I finished with all lights dark, so the backflush from the grey is working to keep the level sensors clear as well as improve the emptying of the black.
Those YouTubers might be onto something.

Were you on a full hook up?

[rssnape]

On my old coach I installed a tank sprayer in the Grey tank in addition to the black. I used a garden hose Y with valves to direct the flow to either tank. Although the opportunity did happen often, when I had sewer hookup at a camp spot I would open the Grey valve and hold the black.

[LETMGROW]

Originally Posted by SmilingSam

I have always left it open to dump BUT always put either a couple sharp S bends in the hose OR a gooseneck vertical bend much like in domestic toilets - to keep the stink where it belongs and NOT in your mh !


GL

Reinventing the wheel? Isn't it easier and more effective to simply close the valve until the tank is nearly full then open the valve and drain the tank?

[Farmboy666]

Before I leave for a trip I put some nice soapy water in the gray and black tank which gives the tanks a nice wash down on the way to my destination. When I start camping I have some clean Soapy tanks.

[LETMGROW]

Originally Posted by Dutch Star Don

Sometimes when you make an all encompassing statement, you need to think about how other RV's are setup and not just your own situation. My full wall slide extends over 30" and then drops down 6", covering all the bays on the driver's side. To access the wet bay means someone very small accesses the bay, or I crawl on my knees. If there are bushes/hedges on that side, it can be nearly impossible.

I've had two back surgeries and both knees replaced. I get around well, but why would I want to punish myself to access the wet bay.

You're right about everyone needs the exercise, but not always the same type. I have to use a recumbent bike to get my exercise, to keep the stress off of my knees.

Didn't you just say in another thread you had electric valves and a Sani-con system?

[tankcj]

Originally Posted by K4LK

After hooking up the sewer we open the grey for the duration of our stay. A friend told me he never does that because the tank could fill with gas from the sewer and end up in our coach! Not sure if the gases could make it past the P traps? What do you do?

Thanks
Dana

I bet you didn’t think you were going to get 8 pages of replies about a silly dump valve did you?

[ET-S]

Originally Posted by K4LK

After hooking up the sewer we open the grey for the duration of our stay. A friend told me he never does that because the tank could fill with gas from the sewer and end up in our coach! Not sure if the gases could make it past the P traps? What do you do?

Thanks
Dana

We have owned 2 campers a class "C" and now a Class "A" you never are to leave the Black tank open until ready to Empty 2/3's Etc.. But I always leave Grey tank open until I need to empty Black tank, Then I close Grey Tank, I use sewer solutions hook up going through a 3/4" or 7/8" hoses with no problems. it was sold @ camping world for several years but don't know now .... so far I have never had a sewer gas problem...

[LETMGROW]

Originally Posted by tankcj

I bet you didn’t think you were going to get 8 pages of replies about a silly dump valve did you?

Or see it picked up and run with nearly two months later.

[Dutch Star Don]

Originally Posted by LETMGROW

Didn't you just say in another thread you had electric valves and a Sani-con system?

Yes I did! I have an electric valve on my BLACK tank which I can operate from inside the coach. There is no need for an electric valve on a grey tank on my coach and how I camp. I also have the SaniCon system which has a grey water bypass, which also can be operated from inside the coach. I can connect my SaniCon hose to the sewer drain faster than anyone here can connect their 3" hose to the coach. I simply open the grey valve and I'm done, the SaniCon allows grey water to bypass through the SaniCon. Since I have macerator toilets, the black water will also pass through the SaniCon bypass. When I'm ready to dump my black tank, I simply flip the black tank switch inside, return in about five minutes and flip the switch off. Tanks drained.

Again, EVERYONE has their OWN reasons for dumping the way they do, from a tent trailer with just sink water draining, to an all electric coach with a washing machine, dishwasher and unlimited hot water for showers. So do what works best for you!

On my daughters fifth wheel, they can walk right up to the valving and open their tanks, no obstructions. On mine, I have to crawl three feet under a slide that is anywhere from 25" to 35" off of the ground, depending on the site. With two knee replacements and two back surgeries, it's not something I like or want to do, so I leave the grey OPEN, which I've been doing for 50+ years.

[ArtJoyce]

I keep them closed until it's time to dump. That way no gas enters. I like to rinse the hose after dumping black with the gray dump.