I guess that kind of eliminates plexiglass as a possibility. I never thought it would bow, so thanks for the information. I checked out some prices online, and honestly the stuff was just too expensive for what I'm looking for anyway.

If I made a cover out of the glass I had, I would probably elect to not hinge it, but rather make it out of a solid piece. Duct tape just doesn't quite cut it for me, and any other hinging method I would find would probably look too tacky. I also weighed the piece of glass i have right now. It was a whopping 50 pounds! Using calculations, I found out that the cover would weight about 8.2 pounds after cutting it to size. Is this too heavy? If I made the cover, I would probably also cut an area for the filter and perhaps the heater as well. This would give me a space to put food in, and would decrease the weight of the cover too. With a space to put food in, I really would only have to remove the cover when the tank needed maintenance.

As for the light, as long as it isn't an eyesore, I would probably use the cheapest light cover I could find and rest it on the glass if I couldn't find a method of mounting it.

If I don't ultimately buy a cover, I will post pictures of the project for those who are still interested.

Thanks again for all the responses!