So, while it is true that the panel needs to be replaced, you're not really telling the whole story here. It's not just a "hey, let me go down to the glass aquarium repair shop, buy a panel, and slap it on there." Structural seams in tanks are very important, and replacing 3 of them on a 265g means you should know what you're doing. This isn't the best tank to learn on. You can certainly try some band aids (siliconing another panel), but in all reality, you'll probably need a new (or used) tank to replace it. The band aids are not structurally sound, and they are not a good replacement for proper technique or engineering. Besides, that solution sounds pretty ghetto fabulous.