Where to buy bird screen in Calgary?

[NastayNatron]

I currently have my tank covered with "Egg Crate". The other day I heard a clicking sound coming from the tank. I looked on top of it to find one of my Barlett's Anthias laying ontop of the egg crate. I immediately put it back in the tank and it is fine. I was very lucky to have been right next to the tank when this happened. She must have just barely fit through the egg crate.

Anyways I want to avoid this happening again. I see people use 1/4" "bird screen" to cover there tanks and would like to add this to mine instead of the egg crate. Where about can I find this in Calgary?