I think you want a bog filter. I am building a small pond with similar restrictions, and finally decided this was the way to go. I initially built the pond with shallow plant area, but I wasn't happy with the look of any filters I made. I am now walling off the plant area for the bog filter. I will pump water from the bottom of the pond, over the wall and to the bottom of the bog filter, where it will be released through a "holey" pipe, and percolate up through gravel to empty back into the pond through a spillway. The top of the grave will be heavily planted, so the filter looks like a garden.

Check the link for a lot more information about making bog filters.

Here is a link that might be useful: Bog filters

Hi Scott. I put in a small pond about the size of yours about 10 years ago. I got a pond kit at Home depot and the pump that came with it ran for about 6 years so I felt it was a pretty good deal. For a filter I just made my own skippy filter and it still keeps my pond clear other than the first algae growth in the spring. You can find out how to make a skippy filter, just google it. It is very cheap and extremely effective.

Hi I've had ponds for 10.years now, I went from a 200 gallon to what I currently have a 5,000 gallon. Depending on the needs fish etc you would determine your filter. If you have fish I recommend getting a mechanical and biological filter. The mechanical part is where the water will run through a series of filters, course to fine, the bilogical is a housing for beneficial bacteria to live. The filter is the heart of the pond, you do not want to skimp in this area. It will cause more work than needed. Over filtration is always better than under. I raise koi fish, an example is, my pond is 5000 gallons my pump and filter and UV are for 6,000 gallons. Trust me on this I've learned the hard way. If you want to see your fish, get a good mechanical and biological filter. If you have any questions at all feel free to ask.

Hi Scott! Welcome to the forums and to ponding, it is quite the adventure.

My small pond is not much bigger than you are planning, it is around 650 gallons, and it too is just outside my front door, along the front sidewalk to the door in fact.

{{gwi:192826}}

Can you find the filtration and mechanical bits and pieces? Oh, and I should confess this is #3 build on this pond. I am a beginner.

By the way, I would do the waterfall part and parcel with the main pond. It will be much easier for you to find and repair leaks without having to worry about fish and plants in the pond. And there will be leaks with a waterfall, and with the plumbing for the bits and pieces.

This is a closer up of the filtration. Mechanical and biological.

{{gwi:192827}}

The pump is in an 18 gallon in ground (actually in pond) tub. It is full of mechanical filtration, course to fine. then I put a 4 way manifold on the pump exit to feed the fountain, spitter, biofilter and the future pond expansion biofilter/falls. The biofilter is an 8 gallon or so pot with an aguatic plant in a mesh planter in the top. Water overflows the biofilter pump into a bog pond. The bog pond runs about 5 feet or so along one side of the pond. The bog pond is planted with shallow water plants mostly in clay orchid pots. I decided not to use gravel since the pond is directly under several messy tress. The bog pond flows over a stone wall back into the main pond. The bog pond is about 20 gallons, and I think that is probably too small.

As for pumps, I've learned from the folks here that mag drives are the bomb. Pondmaster is good.

This is the formula I used to guess-ti-mate pump size:
If you have lots of fish then it's better to have a big pump! You'll want to move the total amount of water through the pump within one hours time. This means that a 2.000 gallon pond will need a 2.000 gallon-per-hour pump. Ponds without fish can do quite nicely with a much smaller pump (or even none at all).
Different pumps have different electricity requirements. Make sure to check the manufacturer's specifications and then do the math before you buy the pump. You could end up with an inexpensive pump, but it will be far more expensive to run.

Total gallons of pond + 3 = Minimum pump size

1" of waterfall/stream surface x 1/2 inch of waterfall/stream depth = 100 gallons per hour

Waterfall/stream width x 100 gallons = Total 1/2 inch gallons per hour

Total 1/2 inch gallons per hour x total 1/2 inches = Total gallons per hour

Watts per hour divided by 1000 = Kilowatts per hour

Kilowatts x 0.10 = Kilowatt dollars per hour )KWDH

KWDH x 24 = Kilowatt dollars per day

I would think that a pondmaster 900 would be the smallest you would want and a 1200 would give you plenty of options for spitters, fountains, and mini-falls.

Hope this helps!

~dianne