LED grow lights last 50,000 to 100,000 hours, roughly 5 to 11 years on a normal indoor schedule (18 hours on in veg, 12 in flower). Premium quantum-board fixtures from HLG, Spider Farmer, and Mars Hydro hit that range. Cheap "blurple" panels fade far sooner, often by 20,000 to 30,000 hours.
Here is what the rating does not tell you: the LED chips almost never fail first. Something else gives out years earlier, and knowing what lets you buy smarter and make your light last longer.
It's Almost Never the LEDs That Wear Out
The diodes are rated for decades. The driver, its capacitors especially, plus cooling fans and solder joints, are what fail first. That is why a quality driver matters more to lifespan than the chip count, and why a good fixture is often repairable, not disposable.
How Long Does Each Type of Grow Light Last?
Lifespan varies a lot by build quality. Here is what each type runs, and the part that usually gives out first.
Type | Rated Hours | Years (18 hr/day) | First to Fail |
|---|---|---|---|
Quantum board (Samsung/Osram) | 50,000 to 100,000 | 7.6 to 15 | Driver capacitors |
LED bar (Spider Farmer) | 50,000 to 80,000 | 7.6 to 12 | Driver or connectors |
COB (Citizen, Cree) | 50,000 to 60,000 | 7.6 to 9 | COB chip, driver |
Budget blurple | 20,000 to 50,000 | 3 to 7.6 | LED chip, fan |
HPS (for comparison) | 10,000 to 24,000 | 1.5 to 3.7 | Bulb replacement |
Why the Driver Dies Before the Diodes
This detail most buyers miss is worth checking before you spend. An LED driver holds electrolytic capacitors that degrade with heat, and grow lights run hot in warm, enclosed tents. A quality MeanWell HLG driver uses 105°C capacitors rated to 100,000 hours. Budget drivers use cheaper 85°C ones that fail in 15,000 to 25,000 hours, showing as flicker, buzzing, or dimming. Look for MeanWell or Inventronics on the spec sheet.
Why Cheap Blurple Panels Burn Out Early
Budget blue-and-red panels die young for one reason: heat. Their small heat sinks let the chip's junction temperature climb to 100 to 120°C, and every 10°C rise roughly halves LED life. Quality boards use big aluminum heat sinks to hold that junction below 85°C, which is why they last two to three times longer. It is not marketing, it is thermal design you can see in the build.
The Trick to Making Yours Last Years Longer
Here is the actionable part most guides skip: dimming extends life. Running at 100% for 18+ hours maximizes heat stress, but backing off to 75 to 80% cuts junction temperature sharply.
The grower's trick: Thanks to the logarithmic power-to-light curve, running at 80% power still gives about 90% of the light. You lose almost no yield but add years of fixture life.
A few more habits help: keep 4+ inches of clearance above passive heat sinks, wipe dust off monthly (buildup cuts cooling 15 to 25%), run your tent exhaust during lights-on, and use a surge protector to guard the driver. For running cost, see our guide on whether LED grow lights use a lot of electricity.
How to Tell Yours Is Wearing Out
Grow lights fade slowly, so the signs are easy to miss. Watch for these.
Lower yield, same setup. If output drops over cycles with identical genetics and conditions, measure PPFD with a PAR meter. Below 80% of the original spec, it is time to replace or supplement.
Dark or dim chips. A couple of failed chips in a 200-chip array barely matters, but past 5 to 10% failure you lose real PAR and get uneven coverage.
Driver noise or flicker. Buzzing, flicker under load, or slow warm-up are driver symptoms, not LED failure. A new driver ($30 to $80) often revives a fixture whose LEDs are still healthy.
Conclusion:
LED grow lights last 50,000 to 100,000 hours, about 5 to 11 years, but the LEDs are rarely why one dies, the driver and heat are. Buy a fixture with a quality driver and real heat sink, run it dimmed at 80%, keep it clean, and it will hold strong output for years. For lifespan across every LED type, see how long LED lights last, or find a durable fixture in our best LED grow lights for indoor plants.
(FAQs):
Q1. Do LED grow lights lose intensity over time?
A: Yes, through gradual lumen depreciation. Quality fixtures lose only 5 to 10% over the first 25,000 hours (the L90 point), while budget ones drop 20 to 30%. Use a PAR meter to track it over years.
Q2. Should you replace a grow light that still works after 5 years?
A: Not for age alone, if it still hits your target PPFD. But efficiency has jumped from about 2.0 to 2.8+ µmol/J in recent years, so a 5-year-old light can use 20 to 40% more power for the same output. Upgrading can pay for itself in 1 to 2 years of heavy use.
Q3. How do LED grow lights compare to HPS for lifespan?
A: LEDs last 3 to 5 times longer. HPS bulbs are rated 10,000 to 24,000 hours but need replacing every 12 to 18 months as they fade. One LED fixture replaces 5 to 8 HPS bulb changes over a decade, saving $150 to $480 in bulbs alone.
Q4. Can you repair an LED grow light instead of replacing it?
A: Often yes, since the driver is usually the failed part. A matching replacement driver costs $30 to $80 and restores a fixture whose LEDs are still good. Match the output voltage, current, and wattage, and it is a straightforward swap.
