There are only 2 choices for pond filters. Either buy a
fancy one or build a low tech one yourself. With either
routes, you still need to buy a water pump to run it.

There are 2 low tech out of pond filters. One is submerged,
whereas all the filter media are submerged, in a tank
outside the pond. This type has pretty good mechanical
filtration as well as biological filtration. A lot of people
here have this type. Perhaps they could post a few links for
you.

The other one is a trickle tower, whereas water drip over
the media. This type has no mechanical filtration. You need
to build a prefilter stage. I prefer this type because it
aerate as well as removes nitrate.

http://la.znet.com/~seannydinh/Filter.html click on Pond
Filtration

My TT is running at only 87 gallons per hour at the moment.
I do NOT recommend running at this rate for your pond, since
you have no water plants. When I get a replacement pump that
could handle 600 gallons per hour at 3' height, I'll stack a
5 gallon bucket on top to increase aeration and degassing
capability. The reason I need a better pump is because I
need faster water changes to filter out the suspended
particles in the water better. At current rate, it's not
doing much for mechanical filtration.

As for UV, I don't use it. I have clear water for a month
since I set up a better TT.

If you decide to build one, google 'trickle tower' and go to
this site
http://www.skippysstuff.com/biofiltr.htm for further info.

DD DDD wrote:

Thank you, I am using 2 350 magnum filters now. They work just ok but I
have to replace the filters every few days. Its jus to much money for
me. I put them under a rainproof hut. Any other thoughts