Replace one side of a tank?

[lockrookie]

mfg got a deal on tempered glass

[Reef Tank Engineer]

Your silicone is fine just use same thickness tempered glass as rest of your aquarium. Make sure all old silicone is off.
For neat edges like your finger and slide up and down corners then when dried(24hrs later) use razor blade to clean up edges of silcone carefull not to break the seal or you will have to reapply silicone and repeat process