How often should grow lights be replaced?
Written by
Kiana Okafor
Reviewed by
Prof. Charles Hartman, Ph.D.Replacing grow lights at the optimum times keeps plant health and energy efficiency at their peak. Different lighting technologies have different life cycles and performance curves. I replace the lighting based on manufacturer recommendations and visible signs of wear and tear. Proper timing will eliminate the gradual degradation of the lights, which would affect plant growth over a month.
LED Systems
- 50,000+ hour lifespan (4-6 years typical use)
- Gradual lumen depreciation after 30,000 hours
- Replace when output drops below 70% intensity
- My panels lasted five years before replacement
Fluorescent Tubes
- 10-12 month replacement cycle
- Ends darken significantly before failure
- Replace entire sets for consistent output
- I mark calendar reminders every ten months
HID Bulbs
- 6-12 month replacement depending on type
- Metal Halide degrades faster than HPS
- Color temperature shifts indicate replacement need
- My HPS bulbs last nine months maximum
Recognizing the cues of performance deterioration is to be done early. Test the PPFD values monthly to determine when the output begins to decline. Look for a shift in color towards yellows or pinks. Watch for a buzzing sound in magnetic ballasts. These occurrences occurred approximately 3 months before the HID failure. Taking prompt action will help prevent stressing the plants.
Increase service life by proper care. Wipe reflectors monthly with a soft, microfiber towel. Dust the lenses of light fixtures quarterly with a can of air. Keep standard voltage to avoid surge damage. These practices increased the service life of my fluorescent light fixtures by four months. Consistent care is the best way to ensure your investment is protected.
Evaluate replacement costs compared with performance advantages. New LEDs utilize energy savings from the day of installation. Consider the annual expenses of the combined technologies. My records show that the frequency of changes for new LEDs is lower than for changes in bulbs in the long term. Observe plant health improvements as a cost on the budget.
Use a staged replacement method. Replace one fixture each month to spread the investment. Note the differences in performance between the new and old fixtures. I keep 20% older fixtures for a uniform result. Hence, your plants have a uniform light without sudden changes.
Read the full article: Indoor Plant Lighting: A Complete Guide
