jt,

All of the external pumps that I am familiar with that are used in ponds do
require some means of priming. This is most easily accomplished with the
pump mounted below water level, though a priming pot and backflow preventer
can be used.

The pumps that you have are large enough, though you may want more water for
the waterfall/stream. The minimum pump size is recommended as one complete
pond change over every four hours. Once an hour is not overkill.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"jt" wrote in message
...
I've had a 300gl pond for 3 years with 2 small (350gph) submersible pumps.
Now I want to enlarge the pond to about 700gl w/a small
waterfall/streambed
and don't feel that the existing filters/pumps will be adequate. I would
prefer to use an external but I'm not sure about these type pumps.
Questions ---
1. Are external pumps suction-type or do I have to mount them below pond
water-level?
2. What pump capacity should I be looking for to ensure good water flow
without pushing water thru a filter too quickly?

Thanks

jt