No need to buy a new tank, you can easily reseal it. I have done it a couple times & once you get the hang of it it is pretty easy.
This is the general instruction:
A few tips:
If all that is loose are the cross braces, you can just redo those. make sure you remove all of the old silicone and all joints are clean & dry. I would do that with the tank empty. Water might push out the panes slightly & give you not quite as strong a bond.
If the rest of the seals are looking dry or loose, you might just take the opportunity to redo the entire tank. You don't have to take the panes apart (unless you have a real leak). just scrape off the inner seals (I use a sharp skew chisel) & redo those. To get neat joints on visible seams, I use masking tape. Mask out each of the seams and smooth each seam (with a latex gloved finger) to the tape. Remove the tape while the silicone is still wet, and you will get a neat straight seam.
If you are uncomfortable resealing your tank, you can have a pro do it. Look for custom tank builders. They do charge quite a bit, so it might not be cost effective.