Improvements on a Skippy Fish Pond Bio-Filter

I like the whole idea behind the Skippy design......

A Skippy Bio-Filter

However I had some ideas of my own to make it more efficient:-

• My pond is not massive (about 400 gallons), so I didn't think I needed a tank as large (or ugly) as a "Rubbermaid" used for the Skippy filter. Please remember that I am not a professional Koi-keeper! I have koi, but not that many and they are mixed with other smaller species of fish. So I don't need a massive filtration system, I just want to improve the water quality and eliminate green water from my small pond the same as many fellow ponders may do.
• Generally a Skippy filter is situated at the top of, and is effectively part of a waterfall, with its large flange outlet, the water literally flows out and down the waterfall (with rubber sheeting around the flange to prevent water leaking behind any rocks which form the waterfall). To accomodate this size of tank into my already built rockery simply was not practical, and I wanted a design with flexible pipe to put the water where I wanted it - in the back of my terracotta urn.
• I particularly liked their "vortex" design, where the pipework creates a swirling motion in the base of the filter, but a "Rubbermaid" is oblong. Using a cylindrical tank would be better to maintain a smooth swirl in the bottom.
• I wondered whether I might find something that looks nicer, and could "blend" into the garden better.
• Rather than having a drain outlet in the side, I thought that a drain exiting vertically down out of the base would help remove filtered solids more efficiently. A Rubbermaid tank has a small outlet in the side, near the base, which is fine for draining just water, but not great for getting gunky muck out of a bio-filter!
• After reading up on "venturis", I wondered whether a venturi dedicated to aerating the filter would improve oxygenation of the aerobic bacteria in the bio-filter.

So there you have it. These were my criteria and ideas for building my own design based upon the Skippy bio-filter.

To see what I did, visit my web site.