2 questions

[Kaia]

First off, I don't have a leaky tank. I would like to know if there is any way to determine ahead of time that a tank needs new seals. It would be nice to know before you run in to problems. Secondly, I've noticed most people have a plain blue back ground. Is this personal preference or is there some sort of benefit to it?

[Ron]

The seal is pulling up near any edges, shows damage or abrasion, appears dry/opaque or is cracking, or seems unordinarily thin, I'd be inclined to preemptively reseal it.

Darker colors are relatively more calming for fish than bright, flashy ones. I think that the blue choice is only personal preference. Lots of people paint the back of the tank, as the benefits are that it's cheap and doesn't allow water to get between the background and the glass, which may cause spotting or weird image transfer problems if you were using the typical tape-on background.

[four_by_ken]

...Lots of people paint the back of the tank, as the benefits are that it's cheap and doesn't allow water to get between the background and the glass, which may cause spotting or weird image transfer problems if you were using the typical tape-on background.

Two of my tanks have this happening and its driving me nuts.