Hello, I'm planning on making some media baskets for my fluval evo 13.5 out of acrylic. Part of my reasoning to do it is to modify the flow of the back filtration area to have more flow through the filtration media. Since I'm probably not going to be able to exactly nail the dimensions of the chambers, I was wondering if there was a good material I could put on the outside of the baskets to ensure the flow goes "through" the media and not "around it". Thanks!