Slow grey water dumping?

dbailey · 08-18-2013, 09:28 PM

We're just back from a short weekend jaunt, and it's time for the newbie question of the week...

I find that it takes a lot longer to empty the grey water tank than I think it should. When I first open the valve, there's a big gush of water (judging just from the sound the water makes in the hose) but it quickly eases off to a slow trickle that goes on and on. I disconnected the host at one point and looked, and saw that the water was consistently draining, but slowly -- the diameter of the water stream was maybe 4 or 5mm. And it went on like this for many minutes, without slowing down.

I think the pad at the dump station was level. And I've observed this before as well, so I don't think it was just a once-off.

So when you're dumping your grey tank, how long does it take? Do you drain it until the flow stops (or at least is reduced to dripping), or do you stop before the tank is completely empty?

Dave Walter · 08-18-2013, 09:36 PM

My grey water tank is quite slow to finish draining also. I don't really worry too much about it and just enjoy the scenery till it is done.

Brian B-P · 08-18-2013, 09:48 PM

It sounds like the bottom of the grey waste tank might be quite level, instead of sloped significantly to the drain. Has anyone looked to see if this is the case?

Anyway, I wouldn't worry about draining the last bit if I didn't feel like waiting - who cares if there's a tiny bit left in the tank? There's even something to be said for not draining off the last liquid leaving bit of solid residue on the tank bottom.

cpaharley2008 · 08-18-2013, 09:51 PM

I found that same result and often after getting home my tank still read 1/3 full. But when I had a campsite that slanted towards the clean out and when I did empty that time, it flowed a lot more and my gauge read empty. Possible that a little tilt towards the street side may help speed and complete emptying.

paulw · 08-18-2013, 10:23 PM

I usually just run the curb side wheel up on a leveler (un-leveler?) block...just takes another couple laps around the rig.

J Mac · 08-18-2013, 10:57 PM

I rock the trailer side to side whilst draining the last dregs of both the black and the grey tanks.

Parker · 08-19-2013, 10:09 AM

Ours is slow to drain as well. After the initial surge, I'll let it drain while I'm adding chemicals to the black water tank, and at that point if I'm out of patience I shut the valve and move on. I doubt if there is a gallon left in the tank. When spending more time to flush the tanks, etc., I'll pull the right side up onto a leveling wedge. I like seeing the gray water tank reading empty when I'm finished, but that's often not the case. Not only is that last little bit slow to drain out, I think the lowest level sensor is pretty close to the bottom of the tank. So while it may read 1/3 full after dumping, I know there is really very little in the tank. I chalk it up to one of the minor quirks of the system and accept it as that.

gharper · 08-19-2013, 07:21 PM

I just drained our grey water tank in our 19 for the first time yesterday and noticed it ran fast then slow for a while. I think maybe next time driving up on my first layer of 2 in levelling blocks on the passenger side to help it along.

dave macrae · 08-19-2013, 08:49 PM

Ours seems to behave as everyone has described , I just wait a couple minutes and it always shows empty when done so that's good enough for me

J Mac · 08-19-2013, 08:58 PM

Queueing up at the dump station gives me anxiety at the best of times. Searching for gear, like levelling blocks,would send me baglo!

Parker · 08-19-2013, 09:31 PM

Quote:

Originally Posted by J Mac

Queueing up at the dump station gives me anxiety at the best of times. Searching for gear, like levelling blocks,would send me baglo!

I agree. That's why I don't wait for it to dribble out that last gallon; I turn it off and pack things up. However, I usually go to a nearby state park when returning from trips and flush out the black water tank and spend a little more time (usually mid afternoon when few people need the facility) and then I'll pull the right side up on a wedge.

gbaglo · 08-19-2013, 09:45 PM

When I left home for the Skagit the monitor indicated black and grey empty. Fresh water full. There might have been two cups of water go down the sink drain and only #1 in the black from camp. I dumped on the way home from the Skagit. Next to nothing in either tank when I started the dump, and I didn't wait for any dribbles. Got home and the monitor said both grey and black were 1/3 full.
Tomorrow, I'm going to put a bucket under the drain and open the grey water and see what comes out.

Dave Walter · 08-20-2013, 08:08 AM

Quote:

Originally Posted by gbaglo

When I left home for the Skagit the monitor indicated black and grey empty. Fresh water full. There might have been two cups of water go down the sink drain and only #1 in the black from camp. I dumped on the way home from the Skagit. Next to nothing in either tank when I started the dump, and I didn't wait for any dribbles. Got home and the monitor said both grey and black were 1/3 full.
Tomorrow, I'm going to put a bucket under the drain and open the grey water and see what comes out.

I think someone is using your bathroom and shower when you are not around.

dave macrae · 08-20-2013, 09:26 AM

That actually happend to us a few years ago at our familys lake lot, I couldn't figure out why one summer our balck tank was filling so quickly every weekend untill I found out that one of our cousins trailers facilitys were broken so their kids were using ours. I sugested that he fix his trailer and was told it was easier to let his kids use our trailer.

Jubal · 08-20-2013, 03:05 PM

I believe the grey water tank is not directly vented on the 19'.
The vent is near the galley sink and upstream from the p-trap before the tank. Resulting in the initial surge and slow discharge.

gbaglo · 08-20-2013, 05:00 PM

Opened the grey water gate and got maybe two cups of water in my bucket. Now monitor reads empty.

dbailey · 08-20-2013, 07:07 PM

I think next time we dump, assuming there's nobody in line behind me, I'll take the time to raise the passenger side on a couple of blocks and see if that makes a difference.

float5 · 08-21-2013, 03:23 PM

We have considered blocks but the trouble is less than just waiting another two minutes.

Jim Bennett · 08-22-2013, 09:33 AM

If there are no lines when dumping, I take the 60 seconds to add blocks to the roadside wheels, otherwise just let it drain for about 2 minutes. LIke baglo found out, I really doubt there is that much left anyway.

After quickly dumping one time, I stopped on a service road on to our property pulling a ways into the ditch giving the trailer lots of side slope. I did not measure, but I bet I got not much more than an additional liter out of the grey tank.

dbailey · 08-22-2013, 11:06 AM

I'm not concerned about getting the last few liters out, but I am concerned about being able to do a good job of flushing the tank. On our way home we usually dump the grey, then run whatever water is left in the fresh tank down the sink, then dump the grey again. If we leave significant water in the tank before flushing with fresh, this will be less effective. Of course figuring out what "significant" means is the issue... And also of course, dumping twice makes the slow draining twice as annoying...

You may also like: