what can i do with 5mm glass??

[Reef Puffer]

i do have two 4' sheets that look to be 6mm/1/4" (barely thinner if u ask me) but are only 14"h and in pretty rough shape if i need to use those somewhere?
i just dont have access to a larger tank in my area, cant afford to get to calgary/vancouver for one without a payment plan, and i have lots of glass. my id sharks just need a bigger tank! i am still in need of a 90g or so for a nice reef DT tho if any one can help....