The Perlite improves the substructure of soil, keeps it loose, allows aeration, and keeps it well-drained. With Perlite No 4, you get bulky and large particles that help maximize the intake of nutrients and improve drainage. The Perlite does not let water rot at the root level.
You can use the Perlite as the standalone medium or mix in element or drip system combined with various other growth systems. If you want to increase the system's drainage power, perlite #4 is the perfect solution.