Decided to remove the canopy and run our rimmed tank open-top for awhile, but want the security of a screen top since it is in a classroom and also we will eventually have more fish. Bought materials to make two half-tops (clear plastic netting for the screen) and watched a BRS video. I have never done any screen work and have a few questions: When you push the spline and netting into the groove do you cut separate pieces for the sides? When you are pushing in the spline is it easy to twist the frame and make it out of square or does it stay square? Do you think it is easy to mess up the first time you try this? I was hoping to make the screens with a few students tomorrow afternoon but I'm wondering if I should try one myself first.