cleaning new pond

I recently received a 150 gallon Tuff Stuff stock tank for use as a pond. It has a chemical smell, and wiping the plastic leaves a residue on my fingers. I assume this is some sort of mold release substance.

Is spraying it with my power washer sufficient to clean it, or should I use some sort of soap?

Also, it came with a brass drain. Is this safe? Should I swap it out for PVC?

Blaise

A good power washing should be good enough. I would hit it with acv first.

I would change our the bulkheads and plumbing to schedule 80 pvc, but the bulkheads are expensive.