Why? Larger Gray than Fresh

[Coacher]

The floorplan I'm settling on has 45 gallon fresh, 45 gallon black, and 90 gallon gray. I currently have something close but the fresh is the largest. In theory a full fresh could be used and exactly fill the gray and black. Of course it never works that way. I've occasionally been forced to dump water from my gray into my black to squeeze an extra day.

I'm assuming the configuration works best on electric and water only sites. In fact I'm thinking it's a superior plan . . . But it seems odd for boondocking.

How's it working out for everyone?

 

[Oregon_Camper]

That is strange. Which floorplan are you looking at?

For reference, our 2023 340RL has 2x53 gallon grey tanks and a 98 gallon fresh tank

 

[M and E]

dump water from my gray into my black

How do you accomplish this? Thanks!

 

[Oregon_Camper]

How do you accomplish this? Thanks!

Use this external valve....this will allow you to open both tanks and allow them to equalize.

 

[Midnight Rider]

Then your filling your grey tank full of crap and you can get back flow Oder up through the drains?
sounds sketchy to me?

 

[M and E]

Use this external valve....this will allow you to open both tanks and allow them to equalize.

That is what I figured. Thank you!

Then your filling your grey tank full of crap and you can get back flow Oder up through the drains?
sounds sketchy to me?

This is what I thought, too, when thinking about how to accomplish this.

 

[Long Islander]

Then your filling your grey tank full of crap and you can get back flow Oder up through the drains?
sounds sketchy to me?

I think the traps on grey water lines would stop the smells from coming up, but I still wouldn't do it. I'd be more worried about causing a blockage by letting the black tank waste to flow into the grey tanks. Having said that I have seen people use the add-on valve to equalize the water level in grey tanks. I just wouldn't do it with the black. I'd be afraid that something nasty would get stuck in the one of the gate valves.

Its just my opinion, but there is probably more grey tank capacity than fresh because most RVs are used in campgrounds with hook-ups. I'd personally love to have a second fresh tank in our trailer.

 

[Oregon_Camper]

I just wouldn't do it with the black. I'd be afraid that something nasty would get stuck in the one of the gate valves.

I have only done this at dump stations with no water to rinse tanks. I empty black tank, then (with full..or close to it...grey tank) I will open the grey for a few mins. There is nothing from black tank pushing stuff to grey...the grey will push water into black tank. Then I close grey valve and open external Valtera valve. Normally this only takes one shot, but if I see it is still very "brownish" I will do it again. I feel there is no way for black to get to grey tank, due to the large amount of grey water pressure from a full tank.

 

[Coacher]

How do you accomplish this? Thanks!

I use a collapsible three gallon bucket and walk it back inside and dump through into the toilet. I look for simple solutions. I didn't want to dump gray on the ground. Although I have put out a campfire or two with gray water.

 

[Coacher]

That is strange. Which floorplan are you looking at?

For reference, our 2023 340RL has 2x53 gallon grey tanks and a 98 gallon fresh tank

252RL Delta

 

[M and E]

I have only done this at dump stations with no water to rinse tanks. I empty black tank, then (with full..or close to it...grey tank) I will open the grey for a few mins. There is nothing from black tank pushing stuff to grey...the grey will push water into black tank. Then I close grey valve and open external Valtera valve. Normally this only takes one shot, but if I see it is still very "brownish" I will do it again. I feel there is no way for black to get to grey tank, due to the large amount of grey water pressure from a full tank.

Makes sense.