The plastic trim around the edge needs to stay on, the fluval base is whats called a "floating base" which means that the pressure and weight of the water gets sent down these supports rather than through the glass so it is less likely to crack the bottom. Just worked out how much your tank when it is full will weigh and its around 220 kilos or 485 pounds depending which you use

So just make sure your unit can hold the massive weight of this. Just a warning as I was tempted but found horror stories dont use flat pack stuff as it can easily split, solid wood units or metal are needed really.
If this is your first tank a good place to read up is
[URL="http
/www.fishforums.net/index.php?showtopic=277264"]http
/www.fishforums.net/index.php?showtopic=277264[/URL] For a new tank I would really recommend the fishless cycle there is an article in there on it and it really is so easy to do and will save any fish a lot of stress and pain and also increase your chances of not loosing any fish
Wills