You can buy nylon mesh material at an arts-n-craft store (eg Michaels, etc). It's used for needlecraft type stuff. I see you have some (at least one) old clip from a HOB
filter pad setup. Use those to clip it on.
The material is fairly translucent and shouldn't look too bad until you figure something out long term.
Now long term, I'd see if I could find someone that could fabricate an acrylic hood (upside down U) that could fit over it after I drilled holes in it for water movement, or smaller slits.