Ten foot lengths of PVC or CPVC, and Krylon Fusion paint. Or the new Rustoleum for Plastic.
Let the paint cure for a full week. Then it becomes part of the plastic, not just a coating on the plastic.
Oh, don't bother painting until you've experimented with diameter and spacing of the holes. Those can be calculated, but experimentation works too. That's why I specified ten foot lengths. ;-)