Cracking Acrylic from Drilling?

[rubytuesday]

Greetings,

I wanted to enlist the opinions of those with some experience drilling existing acrylic tanks. I have a 135g Tenecor that has been up for over two years. I have about 950 watts of metal halides hanging over it in an enclosed wall/canopy. I am going to drill into the eurobrace so that i can add a closed loop into the already existing system. The holes will be for the input and output lines and i will be drilling 6 holes; 4 on one side, 2 on the other. My question is this: Is there risk of cracking? Is there a better time of day? While the halides are on? Off? Will the heat of the acrylic affect it? Is it better to drill with the acrylic hot from the lights? Wait till it cools? I obviosuly want to select the time of day when it would be least likely to crack. Let me know your thoughts.

Thanks!