I am building a 72x36x24 Aquarium. I will be picking up the Acrylic sheets next week, they are 1/2" and already laser cut. I have done hours and hours of research prior to starting this. The one thing that I am now unsure of is between #4 and #42. I've done enough reading and Youtubing that I am fairly confident in using #4 correctly. I have noticed a lot of people mentioning #42. Will I be okay with #4? Thank you for all advice.