Choosing the Light option...

Emporium Hydroponics • February 18, 2026

Lighting choice depends on room size, budget, heat management, and what you’re growing, but modern grow rooms overwhelmingly use LED grow lights because they’re efficient, powerful, and run cooler than older technologies.

Below is a clear breakdown so you can choose the right system.

LED Grow Lights (Best Overall)

  • High efficiency (more light per watt)
  • Lower heat output
  • Full spectrum options (veg + flower in one fixture)
  • Long lifespan (50,000+ hours)


What to look for:


  • Full spectrum (3000K–4000K + 660nm red)
  • High PPFD output
  • Good brand drivers (e.g., Mean Well)
  • Samsung LM301 diodes (common in quality fixtures)


Power guide:


  • ~30–40 watts per square foot (for flowering)
  • Example: 4x4 ft tent → 480–640W LED


Best choice for small to medium grow rooms.


HPS (High Pressure Sodium)

Pros:


  • Excellent flowering performance
  • Strong canopy penetration
  • Lower upfront cost


Cons:


  • Runs hot
  • Higher electricity use
  • Needs bulb replacement


Common sizes:


  • 600W (great for 4x4)
  • 1000W (for 5x5 or larger)


Requires strong ventilation due to heat.

CMH (Ceramic Metal Halide)

Pros:


  • Excellent spectrum quality
  • Good terpene/resin production
  • Less heat than HPS


Cons:


  • Not as efficient as modern LEDs
  • Bulb replacements needed


Common setup:


  • 315W for 3x3
  • 630W for 4x4


How Much Light Do You Need?

Instead of just watts, modern growers use PPFD (light intensity):


  • Veg: 300–600 µmol/m²/s
  • Flower: 700–1000 µmol/m²/s


For most hobby setups, using watts per square foot is simpler:

Grow Space LED Power
2x2 ft 120–160W
3x3 ft 250–350W
4x4 ft 480–640W
5x5 ft 700–900W

Heat Considerations


  • LEDs = easiest temperature control
  • HPS = may need air-cooled hood
  • More light = more ventilation required


If heat control is difficult, LED is strongly recommended!