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Is Spectrum Tuning a Scam? Exploring the Science and Practicality

December 12 2022 – Danielle Daly

Led Grow Light Spectrum Tuning
Led Grow Light Spectrum Tuning


"Spectrum tuning" is a hot topic in the world of indoor cultivation. It's often touted as a game-changer, but are the purported benefits overhyped, and could some of the proposed formulas be counterproductive? In this article, we'll share our thoughts on this subject, driven by a blend of scientific insights and a cost-benefit analysis.

The Focus on End of Day (EOD) Far Red:

Today, we'll zoom in on a specific aspect of spectrum tuning known as End of Day (EOD) Far Red. However, in future posts, we'll explore other popular formulas. One such formula suggests increasing the red spectrum during the flowering phase, with claims of increased yields. Other studies indicate that incorporating additional blue light into the spectrum enhances cannabinoids like THC and CBD. But let's dive deeper and ask some essential questions:

  1. Increasing Red Spectrum: Does it boost yields at the cost of reducing cannabinoids, as suggested by science?
  2. Red vs. Blue Balance: When you ramp up the red spectrum and reduce blue, does it result in lower overall light intensity and yield, given their linear relationship (with an R2 of 0.88)?
  3. Power Adjustment: If your lighting system allows power adjustments to maintain consistent canopy ppfd (photosynthetic photon flux density) during spectrum tuning, what's the maximum amperage per diode? Running them too hot might shorten diode lifespan.
  4. Full-Time Spectrum: Could it be more efficient to have a lighting system with a balanced blend of blue and red throughout the entire growth cycle, along with intense light, aligning with scientific principles? For example, consider the Mammoth Mint White Series, designed with this in mind.

End of Day (EOD) Far Red:

EOD Far Red lighting may seem intriguing, with its promise of encouraging plants to "sleep" faster. However, the reality is that there's no concrete research supporting this claim. In contrast, there's evidence favoring the inclusion of Far Red light continuously in your spectrum, a feature found in all Mammoth Lights.

Scientific Insights: Here's a glimpse into some relevant studies:

  • Kalaitzoglou 2019: This study found that plants lacking Far Red had lower leaf area, plant dry mass, and reduced fruit production. EOD-FR-treated plants behaved similarly to those grown without FR, except for increased plant height.

  • Kusuma et al. 2021: This research revealed that photons during the dark period could delay flowering in short-day plants, and red photons applied at night converted phytochromes, affecting flowering.

Our Conclusion: After reviewing the evidence, it appears that EOD Far Red primarily leads to stem elongation, as seen in the study on poinsettias. It seems to trick the plant into a shade avoidance response but doesn't significantly impact flowering time.

In conclusion, while spectrum tuning is a fascinating concept, it's crucial to critically evaluate the claims and consider the practicality and scientific evidence. We believe in informed decisions based on sound research and cost-effectiveness. Stay tuned for more insights into spectrum tuning and its impact on indoor cultivation.


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