Composting toilet questions and draining grey waste

[Zcashio]

Sorry if this has been asked before. But I'm getting ready to close up the underside of the trailer with the new belly pan and since I will not have any sewer waste from a toilet, do I have to have a 3" connection?? All that will be used is sinks and shower. So no solids at all. Could I just have a 1/2" water hose adapter or at the most a 2" adapter?

Thanks for the help.

[HiJoeSilver]

I think you'd be best off keeping a 3" connection for several reasons. 1. With the nice big pipe you can get a good speedy flush to help get gunk out of the grey water tank. 2. Rv sewer hose size will be 3". 3. Most campgrounds want tight connections between sewer connection and hose, you'll probably have a hard time getting that from a off size hose going into a campground rv dump connection.
You'll still get some solids from the sinks and shower, you want to be able to get them flushed out with a speedy flush.

[LifeIsRiveting]

I came to the same conclusion as HiJoeSilver and I too am about to close up the belly pan with gray only plumbing. It all came down to the fact that 3" hoses are readily available and fit right up to dump stations. It is really hard to find 1.5" hose of any type, especially one that has a smooth interior and is flexible/compact.

So all my plumbing is 1.5" until after the gate valve where it curves 90* and turns into a 3" connection. It's hard to explain but I recently posted some pics on instagram (lifeisriveting)