I looked for several oil film removers, but none were satisfactory. Either the gaps were too large, allowing shrimp to jump in, or they were too heavy to float. I heard that if they don't float, you need to use some kind of sealant. So I simply made one myself where you can insert foam or other buoyant materials. After assembly, you can use super glue to bond it, or perhaps no glue is needed, as it might snap into place. The dimensions have been adjusted for PETG material, ensuring a perfect fit. The pipe I'm using is a 20mm PVC pipe with a 14mm inner diameter