Next, mark an area around your HydroRocks™.
Once you have marked the area completely around your HydroRocks™ - go ahead and remove them and set them aside.
With your HydroRocks™ removed, you can see the outline of their placement.
Next, make a second line outside the first line at a distance equal to the tallest HydroRock™ you measured earlier.
This second line will be the perimeter of your basin.
* Installer's Note: The perimeter of your basin should be away from your HydroRocks™ equal to the height of your tallest HydroRock™ or more to contain the water splash when the pump is running - otherwise you may loose water. *
Next, place your pump chamber inside your outside ring and mark around it.
