On Tue, 26 May 2009 03:15:50 -0700 (PDT), ****gums wrote:

There's also a slight issue of making sure that the narrow flexible hose
from the collar to the tank is exactly level, or it will never fill, or
cause the tank to overflow.

The important level is between the intercepter collar and the hole in butt
side. Water flowing into the connecting pipe will fill that pipe until the
level in it is the same as the collar, if it can't fill the pipe until the
butt is full then the butt will be filled. The interconect can drop down,
what it can't do is go above the level of the collar. Our collar and butt
is joined by a bit of ordinary hose that drops a couple of feet and rises
back up, works fine. Until the bottom of the U fills with crud, which
takes at least a year or three here and is easy to clear anyway.

2) Drop all 3 hoppers straight down.

Why the three hoppers? Seems very odd on a single wall from a single roof.
If the three hoppers can't be reduced to one I think I'd go for:

|_| |_| |_|
| | |
+----+--------+
|
|
|
|
|
| |-+
| | |
|_| +-----------+
Drain

The "horizontal" sections having just a slight fall on them.

--
Cheers
Dave.