I just went through the same stuff.
I finally got a bigger pump tonight. I bought a Wetlands pump at Canadian
Tire which can handle the ponds gph along with the vertical lift. It does
more than what I need it to do so I'll be filtering the amount of water I
want per hour.
You have to determine the total gallons in your pond then add the vertical
lift height. Then choose a pump that can handle all that plus circulate the
water. You also need an external filter that can handle the gph your pump is
throwing out so that you can properly filter the pond.

Here is a great site that helped me decide AFTER I bought a pond kit and dug
the deep section of the pond deeper than the total depth all the way around
as suggestested in the pond kit. I later learned that I drastically changed
the pumps ability to pump & "filter" the water properly so I had to buy a
new pump. I already have a use for the pump that came with the kit so no
worries.

Hope this is helpful to you.

http://www.valleyk.com/water/size.html

--
The~Doofie~Man ©
"LET ME SEE YOUR CIGARETTE LIGHTERS!!!!!"
Putting the fun back in FUNeral!!
http://www.geocities.com/doof70/index.html

"mark" wrote in message
om...
I am building my first waterfall/pond. The pond is 4'x4'x2' deep. The
falls will be only about 3 or 4 feet from the pump and about 4' high.
Can anyone recommend the pump size that I need?