Lifespan Efficiency Curve of High-End LEDs (PAR Output After 3+ Years)

💡 Lifespan Efficiency Curve of High-End LEDs (PAR Output After 3+ Years)

Unlike T5s (drop ~20–30% in a year) or metal halides (~20%/6 months), LEDs degrade slowly.
Aging comes from:
- 🟦 Phosphor degradation (in white LEDs) → reduced PAR, color shift toward yellow/green.
- 🌡️ Thermal stress → lattice defects in diode → reduced photon output.
- 🟪 Short-wavelength LEDs (UV/violet, ~380–420 nm) degrade fastest.
- ⚡ Driver electronics → gradual inefficiency or power fluctuations → can alter current and shorten LED life.

Measured as “L70” → the point when LED produces 70% of original output.

Cree, Luxeon, Osram, Nichia (used in Ecotech, AI, Kessil, GHL, etc.):
- 50,000–60,000 hrs to L70 under proper cooling.
- That’s 13–15 years at 10 hrs/day.
PAR degradation is not linear:
- 🟢 Very flat first 2–3 years (<5% loss).
- 🟡 Noticeable slope from ~5–7 years onward.
- 🔴 Rapid decline after ~10 years.

Assuming quality fixture, good thermal design, ~10 hr/day usage:

Years	Hours	PAR Output (vs. new)	Notes
0	0	100%	Factory spec
1	~3,650	98–99%	Negligible change
3	~11,000	92–95%	Still excellent for reefs/plants
5	~18,000	85–90%	Coral/plant growth may slow in high-demand systems
7	~25,000	78–85%	May need PAR compensation (increase intensity)
10	~36,500	70–80%	At L70 threshold; replacement/rebuild advisable
12–15	45–55k	55–70%	Output no longer adequate for light-hungry species

Reef Aquariums:
- Corals, especially SPS (Acropora, Montipora), are sensitive to small PAR changes.
- At ~3 years, a 5–8% PAR drop may not cause bleaching, but growth may slow.
- UV/violet channels may weaken sooner → subtle color/growth shifts.
Planted Aquaria:
- 90–95% PAR is still fine for most plants.
- However, if the spectrum shifts toward yellow (phosphor degradation), plant morphology and red pigmentation may be affected.

🌡️ Heat: #1 killer. Every 10 °C rise halves LED life expectancy.
⚡ Overdriving: Running LEDs above recommended current boosts PAR short-term but dramatically reduces lifespan.
🧪 Salt creep & humidity: Salt fog etches lenses and reflectors → lowers photon transmission.
🟪 Violet/UV channels: Degrade 2–3× faster than blue/white channels.
📉 Driver electronics: Cheap drivers can flicker, run LEDs hotter, or lose efficiency.

❄️ Maintain good cooling (clean fans, unobstructed vents, passive heatsinks).
🧽 Protect from salt spray (clean lenses, use splash guards).
🔋 Avoid running at 100% intensity continuously — many fixtures last longer when run at ~70–80% capacity.
🧪 Periodically measure PAR with a quantum meter — don’t rely on “still looks bright.”
🔄 Replace UV/violet channels sooner if fixture allows modular swaps.

Ecotech Radion, AI Hydra, Kessil AP700:
- User PAR testing shows ~5% decline in 2–3 years at normal operating intensity.
Public aquaria & coral farms:
- Typically budget for fixture replacement or diode swap at 7–10 years, not because they fail, but because PAR has declined into the 70–80% range.

High-end LEDs retain ~90–95% PAR even after 3 years.
The efficiency curve is flat early → losses are small.
After ~5 years, decline becomes noticeable (~85–90%).
By 7–10 years, fixtures approach L70 threshold (~70–80%).
Thermal management, spectrum (UV channels), and usage intensity determine how steep the curve is.