I want to commend
Narwhal72 for sharing that valuable info on industry reasoning behined the use of tempered glass in production aquariums, nothing like having someone in the "KNOW" to clarify things for those that like to have a good picture of what their about to do and why.
As far as my decision to use the floating bottom or standard (capped) methods, as stated earlier and according to the glass man ordered glass can be off by as much as 1/8 and usually by 1/32, and because my plan is to only to cut out the bottom apart (
never all four sides), the likelihood that the new piece would be too big (1/32) and not float back inside, or too small and have gaps too large would be a major headache and obviously not the way to go. So much so that the original glass-man that had made me the $132 offer for the tempered glass changed his mind when he found out what it was for and grumbled saying
"you need to buy a new aquarium and I'm not helping you measure that glass and if you still want it, it will now cost you $175 to cover my liability" So I asked for the names of some competitors and he quickly rambled off a few names that I later called.
The new price is now $140 and although this new glass-man assures me that new computer cut glass is precise, I have decided to use the standard method to replace the bottom panel mostly because of the great information Sir
Narwhal72 has provided. Obviously this is a much easier method and the one I will be using. As far as use of tempered glass I didn't get a price only the $140 for standard glass but I will be asking that question today when I order it.
The most difficult part IMO is going to be removal and flipping of the side 24x30 panel with the bottom chip but absolutely necessary if I want to make one continuous inside seal, especially since there will be broken un-continuous glass joining seals at the 4 bottom corners as I repeat I will not be dissembling all 5 panels only 2, the bottom and side. so the inside main seal has to be completely removed (last step) and completely reapplied in one continuous unbroken bead.
247Plants - The side panels will never be coming off except for one side piece that will be flipped. because I will be using the standard method where the aquarium is turned upside down and the bottom siliconed on top of the perimeter (instead of inside) of the 4 other panels so the concern of a small size difference is not an issue. The issue now is stability of the remaining 3 sides while working, however I had forgotten about the top center brace which will remain in place. The job wont be a piece of cake but i am confident that with all my years of tech and tool experience in working with robotic weapon systems, I can replace a piece of glass.