In article 3f60b6de$1@shknews01, David Willett wrote:


What is the gph that I want to run through my w/d? I have heard that I need
to cycle the water 3-4 times an hour.

I don't know. Reef keepers often run 10x turn over, but not all of
that is through the sump. Some circulation is just withing the tank
from powerheads.


That seems like an aweful lot of water to
me. It seems to me that it would be a lot easier to run two smaller filters
to get this volume.

There is no real savings useing two smaller filters versus one larger
filter. It is just as easy to run one big filter. But as you have a
long tank it may be easier for you to run dual overflows and
filters. One at each end. You can ofcourse use multiple return pumps,
as well as multiple overflows fed into one filter. A single pump can
also feed multiple returns.


What size overflow tubing do I need?

I haven't found a good answer to that question. The size used depends
on the flow rate. I am betting that 1.25" and 1.5" should be fine as
that is often the size used by commercial tanks. 2" could be overkill.

For a return pipe 1 or larger. 1.25" has almost twice the cross
section area of a 1" pipe so it may be worth useing that slightly
larger pipe. Avoid too many bends and other joints. Use sweep bends
over 90degree bends to get the most from your return pump.

Search google for "durso standpipe" for an excellent low noise
overflow stand pipe. It is really easy to make.