QT Filtration and Cooling

[ecas12]

What are some recommendations for a screen top that can fit an Aqueon 24"x12" 20 gallon aquarium with room for a HOB filter? I currently have some cheap reptile screen top I bought on Amazon that I cut a space out for the HOB filter on, but the air stone in my QT is spitting water onto the top and it is causing it to rust. Also, my QT tank tends to get a bit warm (79-80) when my target temp is around 78 degrees. Again, I bought a cheap aquarium cooling fan from Amazon but it doesn't really seem to be doing the trick. What are some reasonably priced options for both pieces of these equipment?

 

[Spare time]

A QT should be at 81 degrees F (checked with 2 thermometers). As for a lid, I used a mesh lid kit from BRS for my current tank.