Small pond incorporated into a raised bed planter.

[RMaynard]

The typical arrangement would be pond -> skimmer/overflow -> pump -> bog -> overflow -> stream/waterfall -> pond, etc. with the bog at the highest point, and the pump at the lowest. The bog should have capacity for 4-6" above the desired water level so that if the overflow to the pond slows or becomes clogged up, the water can rise above the obstruction without overtopping the sides.

 

[J68R]

I need to spend some time working out the pipe and filter layout, the images I posted are just back of a fag packet sketches.

I've spent time working out the quantities and volumes for building the bed/pond but not yet for the details on plumbing as not got much experience in that regard, as you probably gleaned already. I'll have a good look around at what others are doing and watch a few more YT pond videos, then post something back here.
I revised the calcs on my spreadsheet plan and the pond size, still tiny but up from 150 to around 190 UK gal. which is around 230 US gal.
Bottom course of pond section will be set solid on 3 sides, encased within a 100mm mortar / concrete bed on top of the concrete footing.

 

[GBBUDD]

I think your over complicating things . A 230 gallon set up can be maintained by an oase or even an ehiem professional aquarium filter. If you desire more current you can always add a couple power heads. do 1/3 water changes every couple weeks vaccume and net any debris . Your building an aquarium project not a pond the rules are similar but not