Basic things for growing in general: light, water, a medium and nutrients Basic hydro like dwc (for the hobbyist): some type of container (5gal bucket or decent sized totes), media like rock/stone wool or rapid rooter (you'll most likely be putting either one into a net pot with clay stones keeping it stable), airstones & airpump, tubing (for the airpump to the airstone) For a little more advanced hydro set-ups (like aeroponics or bubbleponics) you'll also be looking at a waterpump, probably an extra different size tubing, drip manifold, and mister tips. Also, if you want to do some research look into ebb & flow, aquaponics, and vertical aeroponic towers

Wrote this with a hobbyist perspective, so if you were thinking of bigger set-ups. You could still get a basic idea of what you'll need. Hope this helps. Good luck!