The Enduring Appeal: Why Some Growers Still Swear by HPS Lights

Despite the rise of LED technology, High Pressure Sodium (HPS) lights maintain a dedicated following among experienced growers. This isn't just nostalgia—there are tangible benefits that keep HPS relevant in today's growing landscape, though these benefits are increasingly niche.

Superior Canopy Penetration

One of the most frequently cited advantages of HPS lighting is its ability to penetrate deep into plant canopies. The intense, focused light from HPS bulbs reaches lower branches more effectively than many LED panels, encouraging more uniform growth throughout the plant.

"I still use a 1000watt hps light. Tried the swap to 2x 240 watt quantum boards and just dont get the same results."

The reality check: Modern bar-style LEDs (600-800W) with proper optics have largely closed this gap. The penetration advantage is most noticeable when comparing HPS to older panel-style LEDs or underpowered fixtures. Quality modern LEDs perform comparably.

Proven Results for Flowering

Many veteran growers report denser, fuller buds when using HPS lights during the flowering stage. The spectrum of light produced by HPS bulbs is rich in the red and orange wavelengths that trigger robust flowering responses in plants.

The reality check: Modern LEDs with dedicated red diodes (660nm) and proper spectrum design produce equivalent or superior flowering results. The "HPS flowering advantage" largely stems from comparisons with early LED technology or improper LED spectrum design.

Cost-Effective Entry Point

HPS lighting systems have a lower upfront cost compared to equivalent LED systems. For growers on a budget or those just starting out, this lower barrier to entry makes HPS an attractive option.

The reality check: While initial costs are lower, HPS operating costs are significantly higher. A £200 savings upfront typically costs £400+ annually in electricity. For anyone planning to grow for more than 6-12 months, LED's higher upfront cost is recovered quickly.

Familiarity and Established Techniques

For growers with decades of experience, HPS lights represent a known quantity. Growing techniques, feeding schedules, and environmental parameters have been refined over years of use. Switching to LED means relearning these variables.

"Been MH/HPS for 20+ years now. I've been contemplating LEDs as they are improving all the time but I'm old and stuck in my ways!"

The reality check: While there is a learning curve when switching to LED, it's typically 1-2 grows to adjust watering and feeding schedules. The long-term benefits far outweigh the short-term adjustment period.

Dual-Purpose Heating

In colder climates or during winter months, the heat generated by HPS lights can be beneficial. Many growers in northern regions appreciate the additional warmth, which reduces or eliminates the need for supplemental heating in the grow space.

"I still use 600w HPS because it's cold and the heat is useful. For taller plants it's efficient to hang the bare bulb vertically and surround the bulb with plants (no reflector)."

The reality check: This is HPS's most legitimate remaining advantage. In cold climates (UK, Northern Europe, Canada), winter grows genuinely benefit from HPS heat. However, for the 6-8 warmer months, that same heat becomes a liability requiring expensive cooling.

When to Stick with HPS

Based on honest assessment, HPS remains reasonable if:

• You already own working HPS equipment — Use it until it needs replacement
• You grow exclusively in winter in a cold climate — The heat genuinely helps
• Your budget is extremely limited — A used £100 HPS beats no light
• You're satisfied with results and don't want to re-learn — That's valid

When to Consider Switching to LED

Consider transitioning if:

• Your ballast or bulb needs replacement (invest in LED instead)
• Heat management is consistently problematic
• You want to reduce electricity bills
• You're setting up a new grow space