Why are reactor reaction chambers always tubes?

[SuperFudge]

Tony,

I have seen a couple of attempts,and it seems that water doesnt want to even flow thru the corners at all(or very little).
The corners usually got so low in PH that they became anoxic.

A way around this would be to build the bottom mesh(the stuff that holds your media from falling thru)so that is blocked in some way at the center....then the water would be forced to go around this and end up flowing in the corners of the reactor.

Marc.