That's easy! You can make a bottomless fishtank, HAHA! j/k...
The span of the glass vs. the 1/4" thickness doesn't really lend itself to holding water if you used them in their existing state. I'd think that the glass itself would bow excessively. Only real option to do anything for fish would be to have the glass cut and make smaller tanks out of it.
If I had that glass in my possession, I would actually have it cut and make glass tops out of it, being that I'm notorious for cracking them, haha....but that's just me

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