DIY Duck & Goose & Dog Pond Filter system

Spouse writes:

The eight geese and two dogs foul up the goose pond in about 4.5 days during the summer. The pond filter we have used for the last few years was a pressurized number that used an external pump. The old pond pump worked under horrible conditions. It had to pump goose poo "soup" continuously. It was stepped on when the dogs jumped in to cool off in said soup. The geese chewed on the power cord while making aforementioned soup... you get the idea. We have gone through a lot of pumps. The current incarnation is more of a pump in a cage. We have a regular 500 gallon per hour pump in this box (http://www.homedepot.com/p/Total-Pond-Mechanical-and-Biological-Filter-Kit-MF13010/202278958). It is connected to a 15 foot length of lead free 5/8 lawn hose connected with a ½ inch adapter. The old pond filter was just too small to take  - err – "soup" and make it spring fresh.

<insert boring design explanation of latest pond filter operation>
I wanted a large three stage filter. The first stage is mechanical filtration at the pump to make sure that the submerged pump runs without incident. The second stage is a a clarifier so that any particulate that makes it past the mechanical stage settles out before the third stage. The third stage is the biological stage. Bacteria - living in some sort of media - consume and filter out the remaining wastes still in the water. For the media, I am using three bags of lava rock.
<end boring design explanation of filter operation>

The resulting filter is part gigantic aquarium filter, part pond filter, and only slightly overbuilt (I hope). I used the filter described here (http://www.runnerduck.com/pf1.htm) as the basis for the new filter with just a few modifications. I switched to 55 gallon drums. I added an extra tank for a clarifier. And swapped out the filter pads for 3 bags of lava rock to host the aquarium bacteria that were going to convert the soup to clean water.

Here is a is the end result...

[the completed project]

Water is pumped from the pond through the light green hose into the clarifier.(the barrel farthest from the pond. The water enters the clarifier from the top which allows the particulate to fall to the bottom and the water flows out the side and into the media tank.. The water is piped to the bottom of the media tank under a plastic screen which is elevated 4 inches off the bottom. View from the top before the lava rock went in. The plastic screen rests on s stand made out of PVC as detailed on the runnerduck page link above.

[media tank BEFORE lava rock was added]

Here it is with the media barrel loaded with lava rock.

First thing I found out was use real bulkhead fittings like these: http://www.homedepot.com/p/1-1-4-in-EPDM-Washer-Bulkhead-MPT-x-FPT-Union-PL-1846-1-1-4-inch-Bulkhead-Union/203258816
Trying to make your own out of pipe pieces scavenged from the plumbing aisle only results in leaks, cursing, and a floor show for the geese who inevitably arrive to supervise.

Second: size the outlet bigger. But maybe not this big:

[the outlet. the filter screen below in the pond was temporary]

That is a ½ inch inlet being drained by a 3 inch outlet. Sort'a of like a grapefruit launcher loaded with raisins. I did have a one inch outlet but that barely kept up. I doubled the size of the bulkhead fitting to 2 inches but all I could find on short notice is the three inch pipe with an adapter.

Here is the inside of the media barrel with water running through it.

The pump has been running for 4 days and the water is just as clear as when we filled it up after cleaning it the last time. The water clouded up for a few hours after I added aquarium filter bacteria but otherwise it has been clear. The animals are certainly using it. The chickens play with the bubbles produced by the outlet stream. One of the dogs, Bandit, has been in it every day as have the geese so the filter appears to be working. We will still have to clean the foam filter on the pump box but that takes a fraction of the time compared to doing a full dump* and scrub. We still need to figure out a way to clean the bottom of accumulated leaves, feathers and whatever else the geese pull into swim with them. But so far the new filter system has been successful.

*d.a. writes: the aforementioned "dump" is actually pumped out to each of the fruit trees. It takes awhile to do so, but we don't waste water here in South Central Texas, y'all.