Im a 1000w Halide 5500k-6000k kind of guy myself. No doubt, HPS will produce more, but there is mounting evidence heavy Blue during flowering, produces more varied chemical profiles, and more varied plant morphology.
Hotrilux has advertised this for year with their 5500k Hortilux Blue. It has also been used for medical research, because of this.
I also kind of digress that LED, are more efficient.
One Question is, how can a light be more efficient, for producing the fullest spectrum possible, that is like the sun, and basically omit the Invisible Spectrum, when 55%, of the Suns Energy, comes from Invisible spectrum? I agree LED has a better overall foot print. But a Hortilux Blue/5500k, and the MMS 1000w Have a spectrum of 280nm-2000+nm, and the same K rating as the sun, at midday.
Also agree both work, and if one lives in a hot climate, and struggle with heat? LED ARE MORE LOGICAL.
What one can do to supply heavier Blue with LED, would be to use ether a Solacure 10,000k UVA/B lamp(s), and a couple of Reptile Infrared Lamps. One need not run the Solacure more than 4 hours per day, or less depending on height from canopy. May not need to run the infrared more than 8-10 hours.
I respect your preference for HID, but there's a lot here that feels more like opinion than evidence. Let's clear a few things up:
1. Spectrum ≠ Efficiency.
Saying a light is "more efficient" because it emits more wavelengths, including infrared and UV, misunderstands how plants use light. Over 90% of useful photosynthesis happens in the PAR range (400–700nm). Beyond that, far-red and UVA can play roles, but just emitting a wider spectrum doesn't mean the energy is efficiently used by the plant.
2. CCT (Kelvin rating) doesn't tell the whole story.
Having a "5500K" bulb doesn't mean it's like the sun. The sun’s spectral power distribution is continuous across a wide range, but metal halides don’t come close to replicating its intensity, balance, or total radiance. LEDs can be engineered to closely target the most productive ranges of the spectrum without wasting energy on heat or unusable wavelengths.
3. Efficiency of LEDs is proven.
Modern LEDs regularly hit 2.5–3.0+ umol/J, compared to HPS or MH which hover around 1.0–1.5 umol/J. That means less electricity for the same, or more, yield, with much less heat.
4. Varied chemotypes ≠ blue light alone.
While light spectrum can affect secondary metabolite production (like terpenes), it’s a complex interplay of many variables, genetics, light intensity, duration, temperature, stress, etc. Blue light alone doesn’t guarantee better chemotypes. If it did, everyone would be flooding flowering rooms with blue-heavy LEDs and getting pharmaceutical-grade output, but it doesn’t work that way.
5. Supplementing UVA/IR with specialty lights makes sense, but that’s a bonus.
If you’re adding reptile bulbs and Solacure lamps, you’re basically turning your grow into a Frankenstein LED + HID + exotic-bulb hybrid just to recreate what modern full-spectrum LED boards already offer, efficiently. You're spending more for less efficiency.
At the end of the day, if HID works for you, that’s fine, but let’s not pretend it’s superior or more efficient just because it emits more total spectrum. The key is what the plant actually uses, and how efficiently the fixture delivers it. LEDs win that battle, hands down, with real-world data to back it up.
