Balancing Grey & Black, Has It Been Considered?

RVNeophytes2 · 07-07-2011, 01:47 PM

As the name implies, I'm still new at this.

In our rig, as in many others, the grey and black tanks fill at different rates. Often, when grey is full, I'm only at half in the black tank.

Lately, I've been washing dishes in a rubber tub that fits neatly in the sink; then, I pour the dishwater down the toilet.

It's magical: the black water sensors are happier, the tanks fill at the same rate, and our "stuff" exits the Rhino hose speedier than that time you ate the bad fish tacos in Playa del Carmen.

It'd be nice if I could reach under the sink and divert the drainwater into the black tank, the cost of this mod would be sub-$20.

Has anyone experimented with this, or has any RV had a crossover/diverter installed as part of its design?

**Route 66** · 07-07-2011, 02:31 PM

We've had several threads on this over the years but I don't recall a diverter.

Mark Nemeth had one solution.

Cat320 · 07-07-2011, 03:32 PM

I don't understand your point. Most of us want the black tank to last as long as possible. I keep the black closed all the time and the grey open all the time, then close the grey a day or two prior to dumping the black. I dump the black, flush the hoses by dumping the grey, then flush the black and grey tanks with the flushing system.

Put some Calgon or Dawn along with a gallon or two of water in the black after you've dumped and are preping it for the next use. That will help the outbound flow...I put some Dawn in the grey tank too, after I close it.

**Route 66** · 07-07-2011, 03:36 PM

Most of us have the gray tank fill up before the black tank is anywhere near full.

Ideally, they both would reach full at the same time.

Quote:

Originally Posted by Cat320

I don't understand your point. Most of us want the black tank to last as long as possible.

**RickO** · 07-07-2011, 04:16 PM

Quote:

Originally Posted by Cat320

I don't understand your point. Most of us want the black tank to last as long as possible. .

I don't think it's an issue at all if you're in a place with sewer hook ups but if you're dry camping for example, it would be nice to be able to utilize your full waste water storage capacity before having to deal with dumping/pumping. There's 10 gal difference in my grey and black tanks and I will still fill the grey numerous times before the black is full.

Rick

okmunky · 07-07-2011, 04:50 PM

Camco makes a tank maximizer that connects the black and gray tanks together in the wet bay. Costs about $25.

I am parked at my daughter's house and use a sewer cap with a garden hose fitting and 25' of hose to drain my gray tank under a huge tree. Of course I am VERY CAREFUL about what I let go down the drain and I move the hose to a different spot daily.

RVNeophytes2 · 07-07-2011, 05:36 PM

Quote:

Originally Posted by Cat320

I don't understand your point. Most of us want the black tank to last as long as possible. I keep the black closed all the time and the grey open all the time, then close the grey a day or two prior to dumping the black. I dump the black, flush the hoses by dumping the grey, then flush the black and grey tanks with the flushing system.

Put some Calgon or Dawn along with a gallon or two of water in the black after you've dumped and are preping it for the next use. That will help the outbound flow...I put some Dawn in the grey tank too, after I close it.

It's for boondocking or being at a site with a community dump station, eg to maximize the time between dumping.

Someone kindly suggested the Camco Maximizer (thanks, great idea), which is similar to what I'd been envisioning, 'cept it backflows grey water into the black tank. I was thinking more of running a tee off the vent.

Of course, you've got the right idea: find places to stay where there is a full hookup. Thanks for the Calgon or Dawn tip. I'll try that. We already went out in search of Calgon for sensor-cleaning, and couldn't find it stocked anywhere. Anyone know where to find this stuff, so common in the 60's and 70's?

LibbyLA · 07-07-2011, 05:42 PM

We found liquid Calgon water softener in our local Wal-Mart, but I didn't remember which section of the store it was in. My SO found it after we searched several aisles. We were looking for the box of powder stuff, not liquid, but the bottle said "water softener".

liz

bigskymt · 07-07-2011, 05:45 PM

Another way is drill a hole in the grey tank dump cap (near the top) and install a 1/4" barbed fitting and a plastic line. Install a 12vdc demand pump in the line and feed it directly to the commode fresh water line. The pump can be wired to your existing pump, another switch or a remote control relay. You leave your grey water dump valve open to feed the pump. Now you flush with grey water and also save fresh water.
Before dumping you close the grey valve...of course you'll get some leftover when you remove the cap.
On my coach the commode is directly above the water bay so easy to plumb.
I drilled the hole in the cap to prevent any "mistakes" from ruining my drain system.

mr300ce · 07-08-2011, 11:40 PM

Camco Maximizer ! That's for me ! Longer desert dry camping, here I come !

Diplomat Don · 07-09-2011, 12:20 AM

If your tanks sit side by side, add a dump valve where you connect your sewer hose. This will allow you to seal off the sewer line while opening both the grey and black tank at the same time. When the black tank is partially full and the grey tank is full, the two tanks will equalize. You only leave the valves open for a few moments and then close both valves.

Our SaniCon system does this just by the way its designed. The other advantage is that the black tank gets a load of soapy grey water that helps to keep the tank slick.

RVNeophytes2 · 07-09-2011, 02:35 AM

Quote:

Originally Posted by Diplomat Don

If your tanks sit side by side, add a dump valve where you connect your sewer hose. This will allow you to seal off the sewer line while opening both the grey and black tank at the same time. When the black tank is partially full and the grey tank is full, the two tanks will equalize. You only leave the valves open for a few moments and then close both valves.

Our SaniCon system does this just by the way its designed. The other advantage is that the black tank gets a load of soapy grey water that helps to keep the tank slick.

Great idea!! And, 'cause of fluid dynamics, the only stuff trapped in the middle section is grey water; it gives two layers of protection from a Robin Williams moment

mr300ce · 07-09-2011, 11:22 PM

Quote:

Originally Posted by RVNeophytes2

Great idea!! And, 'cause of fluid dynamics, the only stuff trapped in the middle section is grey water; it gives two layers of protection from a Robin Williams moment

Robin who ??

mrschwarz · 07-10-2011, 07:16 AM

Quote:

Originally Posted by Diplomat Don

If your tanks sit side by side, add a dump valve where you connect your sewer hose. This will allow you to seal off the sewer line while opening both the grey and black tank at the same time. When the black tank is partially full and the grey tank is full, the two tanks will equalize. You only leave the valves open for a few moments and then close both valves.

Our SaniCon system does this just by the way its designed. The other advantage is that the black tank gets a load of soapy grey water that helps to keep the tank slick.

Wouldn't there be sloshing back and forth? I'm not sure I want black tank contents in the grey tank.