Tanks open or closed when set up?

[David7]

HI all,
We usually keep both tanks closed and then every 2 or 3 days open and discharge the contents of the tanks.
Is there any advantage to keeping them open or opening when there is some volume to off load?
Thanks for your thoughts.
David

[Midnightmoon]

I believe that everyone will agree that the black tank should stay closed until it is time to empty. You will get different opinions on the grey. I personally keep mine open when we are at a full hookup site so I don't have to worry about it. Others will keep theirs closed until full.

[Grumpy]

Originally Posted by Midnightmoon

I believe that everyone will agree that the black tank should stay closed until it is time to empty. You will get different opinions on the grey. I personally keep mine open when we are at a full hookup site so I don't have to worry about it. .

Same here, for almost 40 years.

[David7]

Thanks so much for your quick response.
David

[Marcm157]

I agree with most. Black is always closed. Grey I will usually leave closed as well and just dump as needed. If the whole family is with us I may leave Grey open just for convenience but will close it the day prior to leaving just to have a flown of water to help rinse after final black dump.

[Hazman65]

Black is always closed. If we are camping at a site for a week I will leave the gray tank open for a few days and then close to make sure I have enough gray water to flush out the slinky after draining and flushing the black tank.

[Stavman]

Keep them open

Unless you HATE the smell and stench of poop and dead organisms

Then keep them closed till u dump

[spoon059]

If I'm staying for a while, I'll leave the grey tanks open so we can wash dishes, take bathes/showers without restriction, etc. Black tank is ALWAYS closed, unless dumping. The day or 2 before we leave, I'll close the gray tank to build up water. The morning we leave, I dump the black tank, flush it, then use the gray tank contents to "clean" out the hose.

[SmokerBill]

I'd always leave both closed. Sewer systems in some RV parks are infested with little sewer flies and if the valves are open, they'll infest your tanks.

Ever see little black, slow moving flies hovering inside the toilet? Sewer flies.

[Suprnova74]

I keep mine closed unless actively using the shower (5 people = full tank) then only the grey tank will be open. The black tank needs the water to help flush stuff out and keep things from drying, anyway, imo.

I've seen people arrange their slinky in such a way that it creates an impromptu S-trap. Have it drop to the ground and then up to the slinky guides that run to the dump connection. Makes sense to keep smells and critters out.

[Marine71-76]

We leave ours closed. Like others, if the entire family is there, then we will leave the gray open.

Another family purchased a used trailer that had been parked at a seasonal site for several years. The 1st time they went to use the unit, he called in a panic. Yep, the previous owners had always left the black tank open and there was a poo mound. It took several treatments (forget what he ended up using) plus leaving it filled with water for several weeks to finally dissolve.

[Jagiven]

Black water tank is kept closed until it is 2/3 full or more. You want LOTs of water in the tank to encourage the solids to flow out of the tank.

Grey water tank can be left open. Most people recommend closing it a day or two before dumping the black tank.

Dump the black tank first, than the grey water tank. The grey water will help rinse out the sewer hose.

After dumping the black tank. Always add about 10% by volume of FW back into the tank. You want your black tank to be wet when the solids drop into it, and you want those solids to stay wet. Nothing worse than trying to clear out the dreaded poop pyramid.

[pconroy]

Just piling on - used to leave them open until one campground, the odor came up and out. Luckily no bugs/vermin. Now they're always closed. When the tank is full, it's 3 minutes to pop out and drain. Then reclose.

[TWP723]

I used to keep my grey tank open all the time. Not anymore. I didn't like having and "open" passageway for any kind of anything coming up into the tank. And like a black tank, stuff still settles into your grey tank and rots. Might not be human waste, but it's just as bad sometimes. I've never had any intruder in the tank, just thought I'd be proactive. Not sure it's the correct way to do things but it works for us.

[dmward]

All closed, except I may leave the bathroom gray tank open for showers.

I want as much water as possible to flush out black and kitchen gray when dumping.

[Jopopsy]

I used to leave my grey open all the time when I was hooked up at a campground. Than last year Josh the RV Nerd posted about this very topic saying you SHOULDN'T. Among his reasonings were all the greases and fats from dishwashing and what not end up coating the tank in scum. So last year I kept everything closed until it was time to dump.

FWIW, this year while I was opening things up and sanitizing my water lines, I had no smell coming out of the grey tank when I dumped it. Never had that happen before, I was expecting the typical belch of nasty vile grossness that comes w/ the grey tank.

[ThiloBrown]

The first time I ever went camping. I was like hey lets leave them open then I don't have to deal with dumping.

Left to go the the campground's water park. Came back couple hours later, the inside of the camper smelled like the rankest egg/sulfur smelling farts one could ever smell, lol.


From that experience, I only open when i dump.

[Happy wife / happy life]

Both closed until we are ready to leave. We are usually only at one spot 3 to 5 days. If we are on the road and only staying over night I will dump every other stop.

[RedHorse1]

We have a “sewer solution” instead of a slinky and I leave both grey valves open while hooked up in the CG except when I dump the black tank.

[Flashdman11]

I'm on full hookups and full timer so I keep black closed, but leave gray's open. I do close the gray about once a month and put a cleaner in to help break free any build up that may have occurred, just to be safe.