Backflush black tank from grey tank?

[Scrapper]

My black tank dump valve is a 3 inch, grey tank valve is 1-1/2 inches, both are joined together in a 'T' just before the dump cap.

[DreiHunde]

Interesting. Might be worth a try. It will either work or start the Zombie Apocalypse. Win Win either way!!

[rockfordroo]

Use the Geo Method in your black tank and you won't have to even discuss or argue about this option.

[Springerdad]

Originally Posted by rockfordroo

Use the Geo Method in your black tank and you won't have to even discuss or argue about this option.

Works in the grey tank as well.

[DreiHunde]

Already use the Geo method! Works great, but couldnt resist commenting.... fun topic and it might help even more! roflblack:

[CaptnJohn]

I'll pass on that. After the black is dumped with the valve closed I fill it 1/2 full then dump again. Next the back flush is run for 5 minutes. Close it and dump the 2 gray tanks. Then add 5 gallon of water, a cup of Dawn, and 8 oz of chemicals. The same thing goes in gray tanks. Stays there until the next dump. Be ya problem with sensors either.

[Rvdixie]

Kind of like gargling with the same water you shave with. Doesn't seem healthy to me. Bacteria fighting is tough enough without inviting it.

[CaptnJohn]

Originally Posted by Rvdixie

Kind of like gargling with the same water you shave with. Doesn't seem healthy to me. Bacteria fighting is tough enough without inviting it.

There are 4 bathrooms in our S&B and not one runs to a sink or shower drain before the main line. Code does not permit that.

[MeepMeep]

Originally Posted by Rvlove

We were told by dealer never use your black tank clean out with valve closed if your not paying attention and you over fill there are only a couple of places for that dirty water to go and it would not be pleasant.

Perhaps I should have added this for clarification: I know the size of my black tank and I know the gallons per minute flow of the connected hose. I set a timer for how much water I want in the tank

I never leave this operation unattended and haven't had any overflows in over four years of doing it this way. AND - DW doesn't complain of tank odors

[onetonford]

You guys crack me up. My old fiver you could do that always did for 35 years and never an Issue. I don't see a issue since all my drains in my stick and brick are piped together. I have found thou that if you don't run water down a drain at least once a month the sewer gas will come in. I found that out because it is just me and my wife in a 4 bedroom three bath house we tend to not use all sinks, showers, bathtubs and one night the smell was real strong turns out the sink P trap had dried out.

[DreiHunde]

Originally Posted by onetonford

You guys crack me up. My old fiver you could do that always did for 35 years and never an Issue. I don't see a issue since all my drains in my stick and brick are piped together. I have found thou that if you don't run water down a drain at least once a month the sewer gas will come in. I found that out because it is just me and my wife in a 4 bedroom three bath house we tend to not use all sinks, showers, bathtubs and one night the smell was real strong turns out the sink P trap had dried out.

Well said and great point bringing up household plumbing!! Thank you!

[Tom48]

Originally Posted by dfp

A good friend of mine has done this for over ten years and claims similar benefits and no problems.

If I have the slack in the dump hose, I do that after black drains, by simply lifting the middle of the hose until it is above the holding tanks. Them open the gray, let them equalize then close the gray, lay the hose down and let the blackish drain again. When it stops dripping, close black, drain gray, close gray rince poop tube and put it away?

[Tom48]

Originally Posted by MeepMeep

Perhaps I should have added this for clarification: I know the size of my black tank and I know the gallons per minute flow of the connected hose. I set a timer for how much water I want in the tank

I never leave this operation unattended and haven't had any overflows in over four years of doing it this way. AND - DW doesn't complain of tank odors

Isn't that like bike riders. There are those who have dumped their bike and there are those who WILL DUMP THEIR BIKE.

[Herk7769]

When at a location where you must exist on internal storage and want to extend your stay as long as possible (like the NASCAR infield), I have heard that many folks burp the gray tank (which will fill first) into the black to get another day out of the gray tank.

I tried it once and it works just as advertised. You DO need an "end of line" valve to accomplish this feat to keep from getting your shoes wet when you do finally dump both tanks.

Close the end of line valve.
Open gray water valve to fill the dump mast.
Open black tank valve to equalize liquid levels.
Close black and gray tank valves.
Repeat until both tanks are full.

Attach hose at dump station.
Open end of mast valve.
Dump Black tank.
Dump Gray tank.

[weatherguru1]

Been doing sewer work for years. Good piping is not the dirtiest thing in the world to work on, Septic Systems are. Black water tanks are equal to a septic system. One should never intentionally mix tank products. Get a microscope if you don't believe me.

[Herk7769]

Black and gray water tanks are holding tanks, not septic systems. They don't break down waste, they just hold it till you can dump it somewhere else.

If the swap procedure is done correctly, no solids/TP should ever enter your gray water tank and only gray water will enter your black tank.

As to "bacteria", I can only say that gray and black water mix in the dump mast in any case. The only real difference between the two is an OEM turbo flusher to assist in solids removal from the black tank.

Adding an aftermarket turbo-flusher to the gray tank with make them equal in all aspects.

Don't overthink this.

[CaptnJohn]

Originally Posted by weatherguru1

Been doing sewer work for years. Good piping is not the dirtiest thing in the world to work on, Septic Systems are. Black water tanks are equal to a septic system. One should never intentionally mix tank products. Get a microscope if you don't believe me.

Reading this makes you wonder if some store the sewer hose in their fridge.

[Tom48]

Originally Posted by Herk7769

Black and gray water tanks are holding tanks, not septic systems. They don't break down waste, they just hold it till you can dump it somewhere else.

If the swap procedure is done correctly, no solids/TP should ever enter your gray water tank and only gray water will enter your black tank.

As to "bacteria", I can only say that gray and black water mix in the dump mast in any case. The only real difference between the two is an OEM turbo flusher to assist in solids removal from the black tank.

Adding an aftermarket turbo-flusher to the gray tank with make them equal in all aspects.

Don't overthink this.

DITTO

[youroo]

Originally Posted by CaptnJohn

Reading this makes you wonder if some store the sewer hose in their fridge.

When we installed our "Aeration Septic System" 35 years ago,the Salesman of the system came out afterwards and ask how we liked the Aeration System and told us that the system was so effective the Discharge water going into the Creek was good enough to "Drink" I went into the house and returned with a glass,like Most Salesman he Declined to Drink the Discharge! My point is we treat "Black and Gray" Equal,we are NOT going to "Drink or Bath" in either! I have smelled Galley Tank discharge that would "Gag a Maggot" most added chemicals just "Mask" the Odor,It is Still NASTY! Youroo!!

[jonshonda]

I was discussing this very topic w/ a co-worker the other day, and we figured the grey tank not having a check valve on it would be the reason for not wanting to practice this. But imho it is an excellent way to get the really nasty stuff out of the blank tank.

I know our family produces roughly 2-3 times the amount grey vs. black. So flushing w/ grey would be ideal.

I have also seen that every campsite dumping station we have been to has a fitting at the end which doesn't allow attaching the hose to anything...so this black tank flushing system is useless for us. I am thinking a 5 gal bucket filled and ready to be poured down the *toilet* at the dump station will be our best bet for flushing the black.