In this video, the designer deviated from the age old undergravel filter (UGF) with:
- Bottom drain to extract waste under the UGF, most ponds have one of them. Having that drain hole could be a pain as leaks could happen, but it also eliminated one of the biggest complain about UGF ie gathering of waste under the plate.
- The filter was more elevated from the tradition UGF, almost 1 inch (2 cm?) Probably need more water movement as more water will be under the plate? May be powerhead?
- A felt like sheet between the filter and gravel.