I have a pre-filter sponge on my HOB. I used a black tubular sponge, about 8" or 10" long, can't remember what it was supposed to be used for. I can check though, and brand, if you want. I rubber banded one end closed. A zip tie would be more permanent, but I worried about the sharp edge tearing the sponge on the next step. Once the end was closed with the rubber band, I inverted the sponge and slipped it onto my intake tube. You could rubber band or zip tie it onto the tube, but I did not feel it necessary. I did NOT put it over the intake strainer, I left the strainer off. I also left enough room at the bottom so that there is a good 1.5" of single layer sponge at the bottom of the intake tube, and the wadded, multi-layer bit is farther down so as not to strain my filter too much. It looks much like a boom mike.
Since this adds 4"-6" to the length of your intake tube, and depending on your substrate depth, you may have to shorten your intake tube. There are other pre-filter sponge options, but this one is pretty ninja, very discrete. It works very well for its purpose (mostly to keep sand and fry out of my filter, but does also provide surface area for bacteria).
Now, if I hadn't already had this particular HOB filter, that would have been a different story. So if you're starting from scratch, a sponge or canister may be preferable. Good luck!