Weather Resistant Surrounds? near aquarium

Salt creep will damage your loudspeakers. My 75 gal salt tank caused a salt film to form all around the tank. A fine layer of salt on walls not just visible on tank. You need a indoor outdoor loudspeaker and most of these don't sound so hot. And still salt will age them fast.

Evaporting 2 gals a day! Wow! Poor fish must be boiling. :-)

Seriously, water filtering/management could be a problem and some different methodolgy involved could be a good solution (if you haven't already do so) if you must put a speaker above your tank. And, if you can do it, it will also reduce the noise level from motors/filters and air bubblers substantially in the room and/or tank.

I had a 160gal tank for salt water fish and crabs etc and took my filtering out of the room to the garage. Not only did it quiet everything down it made routine water changes a walk in the park. If your set up allows this, think hard about it. Its really worth the effort, especially if you are tying to keep sensitive species thriving AND not losing the benefits of a high quality audio experience.

I think I am just going to have to move the speakers farther away than I wanted to place them. The next house will have a fish room in the basement, but in this house, the equipment will have to reside in the stand. I built the stand 42" high to accommodate the skimmer. It is a Fish only aggressive tank. I am going to epoxy the inside of the stand to minimize salt creep.

These might fit your needs.

http://www.polkaudio.com/homeaudio/products/multiapplication/products/atrium60/