I have no idea how big a 65G tank is (can you give the dimensions in SI units please?). I think if you were to build a set of doors, you should still seal in a lower glass plate to support the 'ground' and prevent any leaks :)

What sort of lighting are you planning on using? If you are placing this in front of a window you might want it to be clear on both sides, but if not, then I wonder (as you are good at woodworking) whether you might be better off using the glass in a new plywood case. Then you can make it wider, and add any extra features such as sumps and false bottoms.

My metric is rusty. lets see it's 36w x 18d x 24h. If I remember correctly the coversion factor is 25.4 so that would be 914w x 457d x 609h?

After I posted that it occured to me with a false bottom I need a glass panel to at least water level and more likely to slightly above the ground level. This also serves to tie the tank side together and makes it more stable. A narrow peice across the top it probably a good idea too to keep it from try to spread apart. Then my doors could seal against the glass.

I have two 65 gallons and my idea is basically put them side by side. One as an Aquarium and other as a terrarium. So I don't want to build a new box. Plus it will be open on both long sides of the tank and one narrow end.

As for lighting it will be artificial. Most likely CF tubes.

Your dims. in metric are a *little* off. =) Your tank is about 90 x 45 x 60 cm. There are 2.5 cm in an inch, not 25. =)

As for your glass door idea, I think it's a good one. Personally, I don't like any lines in the viewing area, so I would make just one glass piece that you can slide back and forth when you need access to your tank. I believe that this is commonly done with a U-shaped aluminium channel to hold the glass in. Go to www.poison-frogs.com for more info on this, and try to email someone named Homer from this forum. He builds all his own tanks, but he hasn't been here for a while, so you may have a long wait if you just wait for him to chime in. He uses sliding glass fronts on his tanks. If you do a wood frame it will be pretty obvious, and since you tank will be viewable from both sides, it will not be symmetrical, and personally, I think that would look bad. If you don't think so, go right ahead! I am merely voicing my personal preferences. =)

I used to work in a firm that we had to covert everything to MM not CM so thats the reason for coverting at 25.4. Obvioulsy 2.54 would be cenimeters. But, thats neither here nor there.

I like the idea of a sliding door. Would be pretty simple to do I think. My idea was double swinging doors but they would open in the way. These tanks are going to be more of a screen than a true room divider. As you walk into my living room the bedroom door is directly in front of you. The orignal plans had a wall there but we chose to leave it open and use a tank as a divider. So the backside is in a hall more than a room. I am sure guests will step around to the backside to view it. All this to say I agree with your comment about obstructed views. But if I did the door on the back it wouldn't be very noticable and it would give me good access to the tank.

Thanks for the tip about Homer and www.poison-frogs.com

What about an oven style door that pulls out and then up? From memory you can make these using a simple linkage and a spring counter balance. I can't find anything on the web about this, but I reckon you could easily make something up out of mechano.

(My oven door is an old hinge-at-the-bottom design)

Kudzu, I used aluminum channel for my sliding glass door. You can find it at your local hardware store for very little money. With a piece that is 36" in width, you might consider using two parallel tracks and using two 18" pieces of glass so that it is not so bulky. However, definitely have your glass edges ground if you decide to use the sliding glass concept.

Homer

You could build a wooden frame for your terrarium.
http://i141.photobucket.com/albums/r62/hive_man/carnivores/terrarium%20construction/mycarnivoresandterrarium023.jpg
And then you could buy glass hinges.
http://i141.photobucket.com/albums/r62/hive_man/carnivores/terrarium%20construction/mycarnivoresandterrarium007.jpg
Use plexiglass because glass will be to heavy.
then you can purchase a magnetic latch to keep the doors shut.Here is the finished product.
http://i141.photobucket.com/albums/r62/hive_man/carnivores/Large%20terrarium/mostrecentpics052.jpg