with the tank up and running a jig saw might shake the h--l out of your fish...I would lower the water, and cover...then use a router , or dremmel tool to cut...the dremmel will give you a clean cut , and wont shake the tank so bad.I use a jigsaw to cut mine.
thanks for the tip, i plan on only cuttin like two inches longer.bound_for_obx said:It would be a good idea to radius the corners of the cuts as well. A square corner can create stress risers wich can lead to cracks. A rounded corner helps relieve the stress.