Grey tank fills up quickly

[TonyMac]

Originally Posted by keymastr

That could be a really bad idea. The black tank has a vent through the roof for a reason. The gray tank vents are inside the RV, usually under a sink and the only thing preventing sewer gas from entering the coach is a rubber flapper and whatever water is in the P traps. I would not want sewage in my gray tank. The gray tank can smell bad but does not have fecal coliform bacteria in it.

Simple physics prevents that and I've been doing it for a long time. If the tanks are installed on the same plane, like mine side-by-side above the fresh water tank (?) the full gray tank will flow into the emptier black tank in one direction until they equalize in height, not necessarily volume. If the gray is mounted on top of the black, I'd worry about overfilling the black. It could be a really bad idea if the black tank is above the gray tank -- actually, it would be impossible to move gray uphill to the black tank, physics again. But with the tanks on the same plane, the full gray tank cannot possibly overfill the emptier black tank, again, simple physics. If the tanks are on the same plane and the black tank overfills, the gray tank had to be filling the shower floor when we started.

On my rig, there are 3 vents stacks coming thru the roof, both tanks vent thru the roof, as well as the w/d. I'd be surprised to see otherwise. True, there are gray water plumbing vents inside the rig, but these are to allow flow thru the plumbing, just like all those vent lines sticking thru the roof of your home. It is just not practical to run plumbing vents thru the roof in an RV unless absolutely necessary, when they can relieve themselves to atmosphere under the sink.

[Dropthejacks]

We have 2 grey tanks, one for the kitchen and one for the bathroom. With two of us taking showers, brushing teeth, washing up during the day, etc, I usually dump the bathroom grey every 3-4 days. So I don't see where there is a problem. The kitchen fills a bit slower, but I usually go ahead and dump it at the same time while I'm standing there anyway. Black can go a week easy. You can always tell the wife to take quick showers and cut the water off while she suds up, but I like my bride happy, so I'll just keep dumping every 3 days, lol.

Originally Posted by TonyMac

Why don't you move some of that gray water to your emptier black tank?

This I would never do, sewage will end up in the grey tank. Just dump it, it only takes a few minutes.

[okcnewbie]

Originally Posted by lhlee14

We are having to dump grey tank every 3 days. Just two adults.thinking we may have leak. Suggestion on how to go about finding it or other ideas? Thanks

You likely are just using a bunch of water if you are new at all to camping.
If you want to be sure run off of the onboard water tank while you figure this out. Fill up your water tank with about enough water to fill the grey tank. Use the water while monitoring the tanks. Keep in mind some of the water is going into the black tank. Your bathroom sink may even be plumbed to black. Mine is.
good luck

[Duoglide1]

I use a 3rd valve in just that fashion. If the grey tank is full & the black tank has less the water pressure can move it only from higher pressure to lower. Sewage cannot move the against the flow. I open the grey first and close the black first when I’m done-usually about one minute on mine. I can confirm on the tank sensor how much I moved. I do this often when dumping to back flush the bottom of the tank. When I had a hard plumbed macerator on our Monico this was written in the instructions. Good luck.

[sam-3]

If you have a campfire drain some grey water in a bucket to put the fire out before going to bed.

[Mudfrog]

Our tank holds 46 gallons which is more than any other rig we've ever had. We usually go a good three days with the 3 of us. That's showering, washing hands, dishes, and brushing teeth. We do conserve as much as possible when doing all of these things.

Shower: water on to get wet, off to soap up, back on to rinse.
Hands: quick and to the point.
Dishes: water on to rinse off leftover food residue, off for soapy dishcloth cleaning, on to rinse.
Brushing teeth: on to wet brush, off to brush, on to rinse and spit.

I do keep soap at the pedestal and use it at times to wash hands or whatever.

I can see the OP's tank filling in three days, especially if its capacity is less than ours.

[kbhine]

That is about how long we can go, washing dishes and doing a military shower.

[Busskipper]

Originally Posted by lhlee14

We are having to dump grey tank every 3 days. Just two adults.thinking we may have leak. Suggestion on how to go about finding it or other ideas? Thanks

Let's make this simple - UnHook the waterline after filling your water tank.-

Use the onboard water to monitor water usage, Turn off the Pump when not in Use. -

If you have unlimited incoming water - it really is EASY to FILL the Grey Tank! -

When you have a limited amount of Water to put in the Tank it will fill Slower, and you will be aware of what you are wasting water on? -

Give it a try might just solve your problem.

KISS is usually the best way to solve a problem. -

JMHO,

[TonyMac]

Originally Posted by Dropthejacks

This I would never do, sewage will end up in the grey tank.

Do as you please, but no, it will not. Again, simple high school physics. If the tanks are on the same plane, and the water level in the gray tank is higher than the water level in the black tank, water will only flow from the higher level gray tank , to the lower level black tank, until the levels are equal, at which time, water will stop flowing. The inflow of gray water washes back the contents of the black tank. Open gray, open black, count to 10. Close black, close gray. I have a clear 45 below my y-pipe and it fills with gray water, no sewage.

I also use this technique when dumping. Turn on macerator, open black, when black empty, open gray, count to 10 while gray back flows into black, close gray, empty black again, open gray, 1-10, close gray, empty black, maybe do it again, empty black, close black and open gray till it's empty. Turn off macerator. The black tank rinser is running from the first time the black tank goes empty untill 10 seconds after i close the black for the final time. But before I hook up the black tank rinser, I put a few ounces of cheapy walmart dishwashing antibacterial grease disolving dishsoap in the black tank rinser hose and the rinse water blasts that soap into the black tank.

[bgholson]

I have a 60 gallon grey tank. Never boon dock......but without using any water conservation tricks, cooking & long showers for 2 of us my grey tank lasts for 2 nights....sometimes 3. I try to avoid hooking up the sewer hose when traveling so usually dump on the morning of the third day.

[twogypsies]

Originally Posted by bgholson

I have a 60 gallon grey tank. Never boon dock......but without using any water conservation tricks, cooking & long showers for 2 of us my grey tank lasts for 2 nights....sometimes 3. I try to avoid hooking up the sewer hose when traveling so usually dump on the morning of the third day.

Versus us with 65 gal which lasts 12-14 days. Wow! … and yes, we shower.

[ScoobyDoo]

Originally Posted by TonyMac

[COLOR=black][FONT="Verdana"]Simple physics prevents that and I've been doing it for a long time. If the tanks are installed on the same plane, like mine side-by-side above the fresh water tank (?) the full gray tank will flow into the emptier black tank in one direction until they equalize in height, not necessarily volume. If the gray is mounted on top of the black, I'd worry about overfilling the black. It could be a really bad idea if the black tank is above the gray tank -- actually, it would be impossible to move gray uphill to the black tank, physics again. But with the tanks on the same plane, the full gray tank cannot possibly overfill the emptier black tank, again, simple physics. If the tanks are on the same plane and the black tank overfills, the gray tank had to be filling the shower floor when we started.

I'm not real well educated, so there is a good chance for me to be wrong.
I have no doubt, if both valves are open, both tanks will stabilize at the same level. But I think the "can't happen" folks might be overlooking some other "simple physics"; Inertia. The water will rush from grey to black, and maybe until the level of the black is higher than grey. Then it will flow back to the grey, maybe repeat how many times. Is the chance the back-flow will carry sewage really zero?
OTOH, if you do dishes in a pan, dump the pan in toilet. This will reduce the chance food particles stop up the sink plumbing, safely transfer (dark) grey to black, and the soap might help cleaning black at dump time...

[Mr_D]

I've been RV'ing for so long that water conservation is second nature even with the present rig with it's 60 gallon grey and 60 gallon black tanks. I don't know how long I can go with just the 6 cats and I. I know that each tank was about half full after 10 days.

[Oderus]

Originally Posted by TonyMac

Twist it on to the end of the y-pipe where you's twist on your sewer hose. Close the valve to this twist on valve, and open the gray valve, then open the black. Allow them to equalize then close the black and the gray valves. You will have to leave the twist on valve in place and dump with it in place, you can remove it after the dump and flush is complete. Obviously, you may have to determine it you have enough clearance to have both the twist on and the sewer hose connected. And this is very important: The gray and the black tanks must be mounted in the same plane preferable, or with the gray above the black. My Sanicon macerator performs the 'stop the flow' function of the twist on valve.

Yuck. I would never do this. I would equalize both my grey tanks this way but never with the black.