Correct My Sewer Logic

[KamiwillRV]

We are currently on our second trip and this campsite has full hook ups.

I have everything connected as you would expect, but no valves open just yet.

My thought process: I can open the grey and galley valves the whole time, but wait until the end of the trip for the black tank. My thinking is; flushing poo one flush at a time will just leave bits in the hose, and possibly not make it down at all. So I figured I would empty it and flush it at the end.

Am I going about this wrong? Thanks!

[Mr_D]

Fairly close. The only thing I would do is close the grey water valve a day or so before dumping the black tank. That way you can dump the black tank, then the grey. That flushes the black tank "leavings" out of the hose and fittings. Also you shouldn't dump either tank till they're 3/4 full, that helps pull the solids out of the tanks.

[Spk64]

That is a well accepted method that most of us use.
Dump when leaving or full.
Black first then rinse with the grey dump.
Then rinse if you can or want to.

[mikewheel]

Sounds good, close your grey tanks 1 day before leaving and use them to flush out your sewage pipe.

[RoadrunnerII]

Hi
Your thinking is close.
1. Make sure black tank has water in it before you start loading it. Couple of gallons at least. Always ensure you have more water than solids. If solids are too dry they will not drain out.
2. Make sure you have lots of gray water to flush out your sewer hose after you dump black tank.
3. Dump black tank when close to full. If not full add water until it is. More water means faster water flow and better cleaning out
4. Always dump black first then gray
5. If you need to empty Gray's more often make sure you save enough at time of black dumping to flush out your slinky hose.

This is how we do it.

I have seen campers with tower of stinky power in black tank from lack of water.
You don't want to ever deal with this issue!

RoadrunnerII

[Old-Biscuit]

RV Waste tanks are shallow and have a 'lip' where the dump line exists the tanks

Therefore if dump valves are left open the liquids will trickle out as they are placed into the tanks....grey/galley/black

Black tank....
Ever look down into a Pit Toilet?
Big pyramid mound of poop that builds up and all liquid as run off the sides..
So do NOT leave that dump valve open or you will have that poop pyramid

Grey tank....
Body oils, sloughed skin, soap scum etc can also build up when not FLUSHED out

Galley........
Food stuff, oils/greases, soap scum etc can build up when not LFUSHED out


Think of it as a fast flowing river vs a slow trickling creek
That Fast Flowing/High Volume River can move boulders
That Slow Flowing/trickling--low volume creek can't even nudge a pebble out of the way


RV Waste "Holding" Tanks------hold the stuff, wait until full/almost full (add some water if needed) then OPEN the dump valves and let the WHOOSH affect carry the stuff down and out.
Black tank first then Galley then Grey
Add couple gallons of water back into tanks so it can slosh around, keep bottom of tank wet so any stuff left behind doesn't stick and dry out.

[KamiwillRV]

Wow! So many great and fast replies!

Thank you so much!

(Poo pyramid)

[keymastr]

Do not leave gray/galley tank open unless you have a good sized dip in your waste hose making an artificial P-trap or you can get sewer flies in the gray tank which can and will come in the trailer.

Personally I only open the gray valve when I think it is more than half full. Mine is 40 gallons so there is plenty of room for a shower or 2 before even getting close to full.

I also fill the black tank 25% full with water immediately after dumping. Never had a problem doing it that way. Folks who try to conserve water have more trouble there. Lots of water is the key to success. No chemicals needed either. It takes days to weeks for septic tank bacteria to colonize in large enough numbers to digest waste and you will be dumping long before that happens.

[RangeMaggotBob]

^^^
That's the proper procedure. You don't want to leave ANY valves open. It may not smell like poop, but grey water will smell. Empty grey when it's close to being full, but like everybody else says, you want plenty of grey to flush the black when ready, even if you have to add more water to the grey.

[nothermark]

Gray kind of depends. Some folks with high water usage wait until the day before. The rest of us leave both valves closed so that the gray is full when we dump. We just don't use enough gray water in one day to do the job.

[Old Scout]

...nothermark has it right, leave them shut....I don't want my coach sewer system left open/exposed to anyone else's poo system 24/7. Who knows what is down there--and the potential for sewer gas!! Nuf said--know what I mean???????

[grindstone01]

With my wife and her W/D, I would be dumping the gray water tank twice a day, so we leave our's open. I don't think you could mess up the gray tank which ever method you use. There are a lot of ways to deal with the black tank, it's a robust system that most people are scared to deal with and they don't understand it. I leave our black tank open for the last 5 1/2 years which I admit is a not the normal procedure method, but it works for me. No flies, no smell, and no thinking about when to dump.
If you try the open valve method, limit the use of toilet paper into the tank. TP is just another solid in the tank and if the TP does dry out it will be stuck the to tank bottom. Reminds me of a school bathroom where kids would splat wet TP to the ceiling, it was hard to scrape off.

[Cumminsfan]

I never leave the grey or black open for the simple reason that if you get a dry trap in one of your sinks or shower then the sewer gasses could creep up into your RV. Same with the black tank. If your toilet goes dry for any reason then it's an open line to the sewer.
Pew. It fairly simple to just dump when needed.

[YC1]

If you add an outlet valve device that blocks everything you can dump black, close the outlet valve and open gray to allow it to flow into the black until they level. Then close gray and open outlet again. This will give you a couple of quick flushes of the black tank.