old tank

[Leah]

I took the plastic bottom off my 25 gal tank and it is fine.

[parkinsn]

I have taken the trim off of tanks before and never had a problem. Keep in mind if you take it off you need to put some styrofoam under it.

[mike31154]

Some bottom plastic trim incorporates a center brace which also supports the bottom glass, both horizontally as well as under the glass to prevent deflection. Not sure if yours would have this, but even with minor cracks on the trim, it's probably worthwhile to keep the trim on there.

[sphelps]

If it's an old tank in general and showing signs of wear and tear and a new tank is available in your budget I would buy a new one. 55 gallons is more than enough to make a huge mess of your place.