We have 3500 gal main koi pond (12 12-28 inch koi) with water lilies,
underwater plants and marginals on shelves, 250 gal "vegie filter" waterfall
head pond, a gradual waterfall (2 foot drop over 3 foot length), and DIY
filter system built before we purchased home in 1997.

Had a 3500gph Little Giant submersible from 1997-2005 -- least expensive
alternative for flow rate available locally at that time. We were pumping
from the pump in the pond through 2-inch flex line / 2-inch PVC to top of a
50 gallon plastic barrel for first stage of filtering; line enters from top
but discharges 1/3 from bottom of barrel. Two 3 inch pipes near top of first
barrel overflow to two 50 gallon plastic barrels for biological filtering,
then two bottom drains gravity feed back through 2 inch PVC to pond. A 1
inch line to waterfall pond gravity flows from mid-top of first barrel.
First barrel originally held filter fiber matting, and 2nd barrels
originally held lava rock. First barrel now uses window screening material,
and biological filtering material (textured plastic strips) in 2nd stage
barrels.

We want to replace the LG submersible with an external pump. We're looking
at Sequence 1000 Series and considering 5800SEQ23 with primer pot / leaf
basket. We want to place it in-line just before 1st stage barrel, pulling
water through strainer, flex line and rigid PVC pipe. The total linear
distance of hose/pipe from the strainer inlet to the first filter barrel
would be ~12-14 feet, and the total height from the strainer inlet to the
pump intake would be ~5 feet. The filter barrels are in a shed so the pump
would be protected from weather. Cost is currently a major factor, although
in going to the external pump we hope to save by reducing monthly electrical
expenses. Do you think the Sequence will be a good choice for our setup? Do
you think we can configure it as outlined here? It may be a little more
powerful than we need now, but from what I've read, we control that by the
size of pipes used for outlet (between pump and first barrel).

In the future we plan to add a skimmer with a UV sterilizer to far side of
pond and would like to draw water from there, both through skimmer niche and
an attached flex line with bottom vacuum drain (instead of currently planned
bottom line and strainer). If we add the skimmer, can it be used with the
external Sequence pump pulling the water through it to the filter (barrels)?
We may also want to add a stream from the waterfall head pond, but that
shouldn't effect the size of the pump as water is not pumped but gravity fed
to the head pond.

Looking for realistic, on-topic, helpful feedback. Newsgroup filters in full
swing ;-)
--
Zk
Oregon, USDA Zone 7
3500gal pond, 12 pond piggies