Put the 4" drain in the tank floor. I'm working on something similar, coming
out of a 3,000 above-ground tank into 100 gal. tanks for filtration. I'm
using my first tank as a separation tank: the drain comes into it from the
bottom of the main tank into the bottom of the 1st tank. All the tanks are
on a 4 x 4 frame so that they're at the proper height for a gravity fed
system, therefore, the bottoms of the tanks are accessible. Where the
opening in the filter tank is, I found a "T" that's curved on the inside (so
there aren't sharp angles, they're sweeps) to which I put 45* sweeps to give
counter-clockwise water flow (gravity fed). The counter-clockwise flow slows
the water action down, allowing more time for separation to occur before it
progresses to the second (mechanical) filter. A PT 4 x 4 frame (even sitting
on the ground)will hold the tanks off the ground enough to allow the
plumbing connections,

(Elfman Rules!)

Lee

"Oingofan" wrote in message
...
I have a 150 gallon Rubbermaid stock tank and am planning on putting
in a 4" Bulkhead through the lower side of it from my bottom drain.
From what I can see, the bulkhead is just slightly bigger such that it
won't completely be flat against the surface. The area I was
initially going to put in it was opposite the drain.

Has anyone put in a 4" Bulkhead into a 150 gallon stock tank in the
lower part of the tank? If so, how did you do it? Thx!
Oingofan