PoconoRobin wrote:
I have updated my filter design. I was thinking of going with Design #4 on
my web page http://powlusr.tripod.com/Pond/Pond.htm#Update . I would
appreciate comments/suggestions.


You have some broken image links at the bottom, where the attached
images are. Based on your overhead view and side view, a few suggestions.

1: If possible connect the drain to a drip irrigation system, pond waste
water is good stuff for the garden. The mulm has a bit of an oder when
it's first dumped but an hour or two after it dries, you can't smell it.

2: It does not appear that you have a settling area, such as a plastic
drum, it makes it easier to clean the pond if most of the mulm is in the
settling drum. This is how i'd do it, pond - settling drum - waterfall.

I put tube light defuser grills in the settling drum to slow the water
turbulence.

3: Attempt to use venturi nozzles, especially when draining the water is
being gravity fed, free extra aeration. A T shaped pvc connector works
great for this.

4: Upside down milk crates are great for providing shelter for smaller
fish, and act as stands for you to put pots for aquatic plants.

-S