This is a little filter I came up with a ling time ago when needing to
filter small tanks with killifish. It was made by slitting 1 inch
foam threw the middle to male the sponge. The body is a film canister
(ab endangered species) with holes melted with a 16 penny nail amd a
blow torch. Cut an x in the lid for the lift tube to snuggly fit then
Hot glue to attach the lift tube and the airline. To add surface area
and to sink the filter I filled it with large river gravel.
