That's what I use for my 1600 gallon pond.
The pump is inside a 5 gallon bucket filled with lava rock
the water flows through the lava rock to the pump and
then to the veggie filter and back into the pond.
My water is crystal clear to the bottom 4 feet deep.
You can see photos here,
http://radioheaven.homestead.com/Cement_Pond1.html


Ron


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C.R."Ron"Lawrence KC4YOY
Antique Radio Collector & Historian
NCI-5445

POBox 3015
Matthews, NC 28106-3015
704-289-1166 (home)

Radio Collection Web Page,
http://www.radioheaven.homestead.com
Clough-Brengle equipment web page
http://CloughBrengle.homestead.com
CC-AWA Web Page,
http://www.cc-awa.org