Bean Animal Install Question

[DiverDude]

When setting the standpipe heights, how far above/below the overflow line is each pipe supposed to be. I was planning on the main and backup pipes having downturned elbows and the emergency being an open pipe about 3/4" below the rim.

I realize that I can throttle the main drain and raise the level in the overflow to a degree but the whole point of this setup and a coast-to-coast overflow is to get as thin a sheet of water as possible flowing into the overflow.

Right now, I'm thinking of setting the opening of the downturned pipe below the overflow level since the water has to travel up about 3/4" before it can start flowing down the sanitary T.