You can achieve a better canopy and a more balanced spectrum with cfls, I dont think a 100w hps is an effiecient enough light bother with. Just an opinion.
cactusman23 Reviewed by cactusman23 on . Going cheap on an HPS setup? I want to get a 100W HPS setup going, and it looks like I have two options. Here's a ballast for $18, and a bulb for $6: 100 Watt High Pressure Sodium 100 watt HID High Pressure Sodium Bulbs: 1000Bulbs.com And here's a ballast for $50 and a bulb for $17: 100W HPS Ballast Kit S54 Quad Tap - ProLighting.com LU100/MED|C100S54/M|100W HPS Bulb Medium Base Clear - ProLighting.com Rating: 5