One of the key advantages of this tutorial is that the filter is not conceptual or theoretical. I’ve made a half dozen of these filters and my only bitch about them is when I have to break them down for cleaning. But that’s hard to avoid with most filters.

What you need to make 5-gal filter:

1. A hole saw of 1+ inch (Hole saw kit, for 1″ to 1-12″ holes)
2. A drill
3. A Weber lower charcoal grill grate (10.5″ look for stainless for less $) (Weber) (Stainless)
4. Open cell foam 1″ thick or more, for discs at 11-5 to 12″ diameter. (To make 10-11″ discs.)
5. A submersible pump. (Vivosun for cost versus reliability)
6. A sharp, serrated blade to cut the discs with.

Pump should be rated to move half your pond’s volume per hour.

Choose a 10.5″ round grate and stainless is nice for not rusting.