Egg crate will def dim down the lights a lot. I lost the shimmer of my LEDs. Acrylic or plexiglass or whatever will bow unless you use very thick and then it's going to be expensive. Go to lowes or home depot they will cut some cheap or just buy a set. Glass cages.com also has them pretty cheap, don't waste your time trying to save 5 bucks, you will be glad. What are you keeping for fish that jump?