Running Gray Through The Black

[bwaysteve]

Ordering 2 tanks this week.They both slope down from 4 in. to 9"side to side where the 3' collector is. They will be mounted one behind the other.
I was thinking of coming out of the gray 3" and tying into the black directly behind with a gate valve.This gives me the ability to empty the black through a 3" Valterra then open the gate to empty the gray through the black.Any downside or suggestions for connection?

[Ag&Au]

Originally Posted by bwaysteve

Ordering 2 tanks this week.They both slope down from 4 in. to 9"side to side where the 3' collector is. They will be mounted one behind the other.
I was thinking of coming out of the gray 3" and tying into the black directly behind with a gate valve.This gives me the ability to empty the black through a 3" Valterra then open the gate to empty the gray through the black.Any downside or suggestions for connection?

I have thought of running a line from near the drain of the gray tank to a pump that would dump into the top of the black tank. My purpose would be to extend time between dumps. We always fill the gray way before the black.

Regards,
Ken