From the guy who started the DIY aquarium moving bed filters - New design based on the original moving bed filter. It still uses a bottle to house the K1 but also uses 20mm pipe, foam and heater clips/suckers to ensure that the water will be mechanically filtered (foam) as well as biologically filtered (moving K1 media). This will be perfect for breeding tanks as fry can feed from the foam and the K1 can cope with a high feeding regime - all run from a small air pump!
This should be the only filter you will need in an aquarium and since you should have an air pump anyway, the running costs of a traditional internal filter can be taken out of the electricity costing.
Perfect for a fish house with multiple tanks, instead of having either a sponge filter or internal filter, a combined moving bed filter can be installed in each tank to totally filter the water - all run by one air pump.
** I AM NOW SELLING A NEW MEDIA WITH 40% MORE SURFACE AREA THAN K1 - CHECK LINK BELOW **
To buy the media (I ship Worldwide) and make your own filter, please follow this link:
A better, production ready design using a new media can be seen on the video 'Excellent moving bed filter at Tyne Valley Aquatics' and the new media should be available spring 2012.