Pond Boss Forums POND CONSTRUCTION Creating habitat Porcupine cribs

I bought some "porcupine heads", that hold 26 pieces of 1/2in PVC. I like that you can cut them to handle any pond depth. Has anyone used these? Do you pre-sand the PVC so plankton will attach?
https://www.amazon.com/Cedars-Dance-Porcupine-Attractor-Spheres/dp/B001BAAVMK