I was having trouble making a proper cover for it because I noticed my dear HMDT Leo's tail had gotten torn from fighting it.
I tried using a stocking, which worked. But the gunk that got stuck in the fibers of the fabric would eventually cause the entire filter to stop altogether!
Cutting holes in the stocking helped but didn't work very well to keep the intake strong.
then I remembered someone making a betta hammock out of some plastic mesh (used for making decorative rugs) from the craft's store.
Then it hit me: I could put a little of the mesh inside the water intake tube! It'd block Leo's fins from getting caught in the suction and let the water move freely because the holes are large!
The mesh is called "Plastic Canvas" and looks like this:
and I got a big haul of it for only 3 bucks at my local Wal-Mart!
For the PF10 models the intake tube is detachable. So you would detach it from the main filter and do a guess of how wide and how long you'd need to cut the section of plastic canvas. Once that's done neatly cut along a row on the mesh (try not to leave sharp points!) and slip it into the tube.
It is stiff you can roll it and it'll line the inside of the tube. If it's too big, cut a little more of the mesh away and try again.
Reattach it to the filter (if its hard to put back then the mesh is too long and you'll need to cut a little off the top!) and boom!
Safe water intake for delicate, long fins :)