I want to drill a hole into the top right back panel of my tank but I dont know if the back panel is tempered or not. The dimensions 24" wide x 20" high x 12" deep = roughly 25 gallons. The tank was a hand me down from my sister probably about 6-8 years old. I can see a sticker that says "built by H.A..." But i cant see past the "A". Is there any way to tell if the front and back panels are tempered? I want to avoid using a U tube, and use a bulkhead fitting with an attachment.