HPS vs. LED Grow Lights: An Honest Guide for 2024
Our Honest Recommendation
For most growers in 2024, LED is the better choice. Modern LEDs have closed the performance gap with HPS while offering significant advantages in efficiency, heat management, and long-term costs. If you're starting fresh or replacing old equipment, we recommend investing in a quality LED fixture.
That said, HPS still makes sense in specific situations—particularly if you already own HPS equipment, grow in cold climates where heat is beneficial, or have a very tight initial budget.
The debate between High Pressure Sodium (HPS) and Light Emitting Diode (LED) grow lights has evolved significantly. While HPS dominated indoor growing for decades, LED technology has matured to the point where it's now the preferred choice for most new installations. Here's an honest breakdown to help you decide.
The Reality Check: LED Has Won (For Most Growers)
Let's be upfront: LED technology has surpassed HPS in almost every measurable category. Modern LED fixtures from reputable brands like Spider Farmer, HLG, Gavita, and Mars Hydro offer:
- 2.5-3.0 µmol/J efficiency vs. HPS's 1.0-1.7 µmol/J
- 50,000+ hour lifespan vs. HPS's 10,000-12,000 hours
- Full-spectrum light optimized for all growth stages
- 70% less heat output, drastically reducing cooling costs
- Dimmable controls and smart features on many models
Initial Investment Comparison (2024 Prices)
| Factor | HPS (600W) | LED (Equivalent Output) |
|---|---|---|
| Light Fixture | £150-250 | £350-500 |
| Additional Equipment | +£100-150 (cooling, extraction) | Minimal |
| True Initial Cost | £250-400 | £350-500 |
While HPS appears cheaper upfront, when you factor in the cooling equipment required to manage HPS heat, the initial cost difference shrinks considerably.
Ongoing Operational Costs: Where LED Dominates
| Factor | HPS (600W) | LED (400W equivalent) |
|---|---|---|
| Actual Power Draw | 600W + cooling (700-800W total) | 400W |
| Monthly Electric (12hr/day, £0.34/kWh) | £85-95 | £50-55 |
| Annual Electric Cost | £1,020-1,140 | £600-660 |
| Bulb Replacement (annual) | £40-60 | £0 |
| Annual Operating Cost | £1,060-1,200 | £600-660 |
The Bottom Line
Annual savings with LED: £400-540
Even if you pay £200 more upfront for LED, you'll recoup that within 6 months through electricity savings alone. Over a 5-year period, switching to LED saves approximately £2,000-2,700.
Performance Comparison: The Truth
| Factor | HPS | Modern LED |
|---|---|---|
| Light Spectrum | Yellow-red dominant (limited) | Full spectrum, customizable |
| Efficiency (µmol/J) | 1.0-1.7 | 2.5-3.0 |
| Canopy Penetration | Excellent | Very Good (improved significantly) |
| Heat Output | High (70% as heat) | Low (30-40% as heat) |
| Yield Potential | 1.0-1.5g/watt | 1.5-2.5g/watt |
| Bud Quality | Excellent (dense buds) | Excellent (improved terpenes) |
When HPS Still Makes Sense
Despite LED's advantages, HPS remains a valid choice in these specific situations:
Consider Keeping/Using HPS If:
- You already own working HPS equipment — No need to replace functional gear immediately. Use it until it fails, then upgrade to LED.
- You grow in a cold climate/unheated space — HPS heat can reduce or eliminate heating costs in winter.
- You're on an extremely tight budget — A used 600W HPS kit for £100 beats no light at all.
- You're growing plants that specifically benefit from HPS spectrum — Some flowering plants respond well to the red-heavy HPS spectrum.
- You have excellent, free ventilation — If heat removal is essentially free (cool climate, existing extraction), HPS cost-benefit improves.
Recommended LED Alternatives
If you're ready to make the switch from HPS, here are our top recommendations based on your current HPS wattage:
Replacing 1000W HPS:
- Spider Farmer SE7000 (730W) — £600, best value. View on Amazon
- HLG 650R Diablo (630W) — £1,100, premium USA-made. View on HLG
- Gavita Pro 1700e LED (645W) — £999, perfect for existing Gavita users. View on Gavita
Replacing 600W HPS:
- Spider Farmer SF4000 (450W) — £400, excellent value. View on Amazon
- Mars Hydro FC4800 (480W) — £400, modular design. View on Mars Hydro
- VIPARSPECTRA XS4000 (400W) — £330, budget-friendly. View on Amazon
The Transition Strategy
If you're currently using HPS and considering LED, here's our recommended approach:
- Don't rush — If your HPS equipment works and you're happy with results, continue using it.
- Plan for replacement — When your ballast or bulb needs replacing, invest in LED instead of new HPS components.
- Consider hybrid — Some growers run HPS in winter (free heat) and LED in summer (less cooling needed).
- Budget over time — Save monthly electricity savings toward your LED purchase.
Important Note on Switching
When switching from HPS to LED, expect a transition period. LED requires different watering schedules (typically less frequent), nutrient concentrations (often lower), and environmental management. Your first LED grow may have a learning curve—this is normal.
Final Verdict
For new growers or those building a new setup: Go with LED. The efficiency, lower operating costs, and reduced heat make it the clear winner.
For existing HPS growers: There's no need to panic-switch. Your HPS still works. But when it's time to replace equipment, LED is the smart investment. The long-term savings are substantial, and modern LEDs produce results that match or exceed HPS in both yield and quality.
The indoor growing industry has moved to LED. While HPS served us well for decades, it's time to acknowledge that LED is the present and future of indoor lighting.