[danny zubot]

In the case of smaller tanks, the brace is there for the seams, not the glass. IE: When have you ever seem a 10 or 20 gallon tank bow.

I replaced the center brace in my 65 gallon with a 6 inch wide piece of half inch glass that bow valley cut for me for like 10 bucks. If you want to use plexi, double it up because you want it to be pretty thick so as to
have lots of surface area for the silicon to grab.

Also, Quick grow can make a custom reflector for you, but you will pay a bit more. Since you will be using real reflector material it will still beat any tin or reflective material you'll find at Rona etc. Well worth the extra bucks IMO.