What a great thread! I wondered how I'd missed it before.... and then I saw I actually had posted on it!
Funny how different my designs went from them to now.

It's amazing how designs have changed over the last 15 years or so. Settling chambers and self cleaning micro screen were
the rage.

It takes some time to draw up how the ponds work but, as was said in the beginning, it'd be very helpful I think for new pond
builders coming up to see different designs.
My lower pond is unique in that it doesn't use BD's but has a trough that sits about 6" lower than the main floor of the pond
and it has 8 air lift tubes running from it up and out to an overflow that runs into the yard. The debris collects in the trough
and is pulled up and out by the airlifts. Makes water changes and maintenance a breeze.

Lower pond:

Name:  lower pond filter plan.jpg
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More conventional upper pond:

Name:  Upper pond filter plan.jpg
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