aldiaz33! This is great news! I'm worried about my 450 being in a window I've even put a wallpaper on the back and top to try and stop UV radiation from reaching the acrylic but I'm pleased to know that I was wrong!
My tank I got from Aceface and was constructed earlier this year so I'm confident that it's newest materials.
Glad to hear it. I had an acrylic 270G that would get direct sunlight for a few hours every day for 2.5 years and it did not yellow at all. I got it used (it was about 8 years old). Plastic will yellow over time when exposed to UV light, but cast acrylic should not.