This is a 400 watt Metal Halide fixture. Make sure you have a large reflector, like the one shown.

This is a comparison of an industrial high pressure sodium light (left) and a Hydrofarm on the (right). They both work well, but I believe the grow light to have superior characteristics.

Here is a conversion bulb. This Sodium bulb was made to operate on a Metal Halide ballast.

I found this sweet ventilation fan at the Home Depot. It works well for moving fresh air in, or sucking old air out. Wire one up like I did.

This digital thermometer is great for monitoring the air temperature. It also, has a wire, which is submersed in nutrient to give a water reading. Just flip the switch air/water. Hydroponic lighting and proper ventilation are key to success. (Page2)