I finally broke down and bought a canister filter, even though I thought I would always be happy with my el-cheapo sponge filters that have been working just fine.
Flow/current: My first question is regarding placement of the input and output in the aquarium. Should it be set up to have the output at one end of the tank, and the input at the other end, with the flow/current mostly in a single direction? Or should it be set up in a circular flow: for example, the filter output into the tank at (from top view) 1’oclock facing towards 2 o’clock, then then the filter input sucking from the tank at about the 12 o’clock position. Water would flow (in theory) all around the tank before going back to the filter.
My next questions are about modifications of the input & output.
Filter output to tank: Have you guys modified the output into the tank? Instead of a single output near the top, I was thinking about installing a vertical tube, with holes drilled into it along the entire height. This could create flow along the entire height of the tank and not just at the top. Has anybody set up or recommend using a spray bar above the surface to create more surface agitation?
I’m also wanting to attach a coarse sponge filter(s) to the filter input. Are there larger round ones available to fit over the regular fluval input, or do I need to find a sponge block and custom make my own?