I still can't find the post
Oh well here's what to do and look out for:
Run the hose to the deep end corner (a lot of water truck drivers will try to fill at the closest point, make the lazy SOB put on another length of hose

).
Start the flow slowly and have someone holding and aiming the flow (to make sure the hose doesn't 'snake' around and that all the connect5ions/ hoses aren't leaking. The person holding the hose should aim the flow at a wall to deflect the force and it helps if they cup their fingers over the flow to further deflect the force.
Once you've got ~ 6" in the hopper, kill the flow and install the MD faceplates, cut out the liner and install the covers.
Start it back up, as before.
Once you've got a couple feet of water in the hopper, direct the flow into the center of the hopper.
The reason for deflecting the flow off a
deep end wall is to prevent floor wrinkles. If you just let it go into the shallow end the force of the water can wrinkle the shallow end floor and/ or the slope (try to imagine the force of 300 gal./ min.

)
I'm not saying that you are guaranteed to get wrinkles if you fill from the shallow end, but why risk it?