Some pumps need to have some form of protection from the debris that they
pick up and try to grind up. Some pumps will handle solids up to 3/8 inch
or so. If the pump will handle solids, it grinds up the solids into a puree
that is much harder to filter. If the solids can be collected before they
go to the pump, by settlement basin, media strainer, clam shelled plant
baskets, or whatever, then it is that much less that must be digested by the
bacteria in the pond. A prefilter outside the pond is much easier to clean
than the in pond prefilters that require you to lift the pump and as you do,
a cloud comes up around the filter material.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"Iain Miller" wrote in message
...
Anybody have an opinion on which is better & why? Anybody tried both &
found
one to be much better than the other?

I would think the pump fed is easier to set up & is not sensitive to water
levels in the pond but the gravity fed seems to have the advantage of
being
able to catch a lot of the cack in a settlement chamber and less pump
maintenance.

I'm trying to decide on which way to go - what's the preference of the
assembled company? All thoughts gratefully recieved.

rgds

I.