how to place PH and Eductor Return?

[bighaig]

I have a 88G rectangular tank with the overflow in the rear right corner. How should I place the PH's and the return pipe which has an Eductor on it?

Equipment:
2 x Seio 800
1 x QuiteOne 3000 ~600Gph with Eductor on end of return

Questions:
1) How deep should I place the Eductor? What lvl will it start pushing the sand around?
2) How should I place the PHs?

http://bighaig.com/88g.JPG

Thanks

[BurntOutReefer]

trail and error my friend....
doesnt look like any flow towards the bottom

[bighaig]

Should there be flow on the lower levels?

[bighaig]

:confused: bump