Combining black/grey tanks

[Scottybdivin]

Originally Posted by blang

At the end of your outflow pipe, attach the clear elbow (or they make other configurations like straight long or short, too) and then the new gate valve. With the added gate closed and the other two opened, you will see the water moving through the clear. Again, just make sure to open the black last and close it first when the flow begins to slow... to keep the... um... black in the black tank.

Here are some examples of the clear I'm referring to. Basically, just use whatever your configuration and space calls for. And, by the way, there are more of these available. These are just to get you moving in the right direction. Um... no pun intended. Well, ok, maybe a little pun.

https://www.amazon.com/Valterra-T102...words=valterra

https://www.amazon.com/Valterra-T102...words=valterra

https://www.amazon.com/Valterra-T102...words=valterra

I already have a clear elbow that remains connected all the time, but it is below the wye that connects the gray and black lines together. I assume that you are saying that even though the elbow is below the wye, you can still see the direction of flow?

[blang]

Originally Posted by Scottybdivin

I already have a clear elbow that remains connected all the time, but it is below the wye that connects the gray and black lines together. I assume that you are saying that even though the elbow is below the wye, you can still see the direction of flow?

Yes, you can see the direction of flow as well as the speed. Even in the grey tank, there are little bits of soap, etc that you can see. Also, since you're opening the black last and closing it first, you KNOW which way it's flowing... now you just have to close the black valve when you see the flow slowing. In theory, the tanks will equalize in volume if you wait until all flow has stopped. Personally, I choose to close the black before then so that I know the black solids remain in the black tank. In reality, I guess it really doesn't matter. Then again, waiting will also increase the odds of getting a solid cut in half in the valve when you close it... which may affect the integrity of the valve.

[CountryFit]

walmart has a 90 degree clear elbow.
i have used it with a gate valve for years it transfers between the tanks no problem.

[carl2591]

We are looking at going the compost toilet route and talked with other about combining gray and black tanks. I was told to make sure the black tanks was VERY clean before combining the tanks.

Some folks will have the tanks professionally cleaned with hot high pressure water cleaning to get all the "stuff" out.

The unit we bought had very little black tank usage over it life and it has a nice black tank cleaner built in. When we do camp, which is low now, we tend to use the rest room at bath house more especially for #2 stuff..

If we do have to use the tanks more with camping i plan to do a good cleaning of black tank before combing tanks. ( I have a power washer at home) LOL...

If you have a older unit with LOTS of black tank usage then the issues noted above could be valid. I think it a good idea to go compost and to have black tank thoroughly cleaned before combining tanks for everyone sake.