Yup, the nylon pan scrubby things.I've seen ppl use stainless ones, but nylon it is.Another thing I was thinking is maybe making 2 of the DIY filters using 5 gallon buckets, figure they'll be easier to hide, and probally just use a pet co or home depot waterfall then.I wish I knew some ppl in my area with ponds and filters to go look at and get some ideas.Still working on a filter system in my head to try to loop 3 55gal tanks together on 1 system.Using canisters now,but 1 big system for them all would be nice.