tank rebuild

Please guys, can you share some ideas on this? and maybe if you've experienced like a failure, large or small with any brand, feel free to let us know.

and then hopefully rebuild it. I asked the Monster guys next store, and they pretty much agree, it's gotta happen if the Puffers are gonna have a pond in the house. Its a 185 double waterfall tank. The same kind they had at Petco years ago. It was once pretty regal, so we'll see how it go's...