Here's how to build a one-of-a-kind water feature in a weekend. This water feature consists of an underground, waterproof basin; sturdy grating; and a pot of your choice. Most of the supplies you will need can be found at a plumbing supply or hardware store or a nursery that carries water garden supplies. Step 1: Plumb the pot For this step, you'll need your decorative pot, a 1 3/4" by 1" barb fitting, a 1 3/4" PVC female a