Grumpy wrote:
Benign Vanilla wrote:

"gng" wrote in message
...

I have a Sequence 7200 and Aqua Ultima filter. The original guy who built
this used 1.5 inch, but when you do the math you actually get nearly twice
the water with 2" pipe. Been told the intake is the most important place

to

have the larger pipe. Sequence told me to use 3" if I could for even more
flow.

snip

I would agree. Never restrict the input to your pump.
BV.

The 3" to the input is no problem. The bottom drain and skimmer are
plumbed for 3". It's the output I have concern for. I want as much flow
as possible to the falls. Will I be able to do 3" from the Ultima? Thanks

The pump doesn't give a rip what your pipe diameter is, all it cares about is
the static and dynamic head. Bigger pipe gives you a smaller dynamic head for
a given flow rate. You *might* run into the situation where the system is
overdesigned (dynamic head is so low that static head is all the pump is pushing
against), but I doubt you'll run into that situation with only 3" pipe. If you
want to be sure, figure out the system's dynamic head from the tables referenced
in Richard's post, and check against the flow curves for your pump.