Far Red vs Standard Spectrum: Does It Boost Yield?

What is far red as a listing term

Far red refers to wavelengths of light in the 700 to 800 nanometer range, just beyond the visible red that humans see. On a grow light listing, you may see phrases like "660nm red" or "730nm far red" or simply "far red diodes." These terms tell you that the light includes LEDs that emit in that part of the spectrum.

The listing does not always explain what far red does for plants. Some makers include it to broaden the spectrum, while others highlight it for specific stages such as flowering. Because this site reads only the stated details on the listing and the maker’s page, it cannot confirm any effect on plant growth or yield. The best source for that information is the maker’s own product description and manual.

Standard spectrum (full spectrum) as a listing term

Standard spectrum, often called full spectrum, is the most common term on grow light listings. It means the light emits a broad range of wavelengths from blue through red, and sometimes includes far red. A full spectrum light appears white to the eye because it combines many colors.

When a listing says "full spectrum" without further detail, it usually covers the photosynthetically active range (400–700 nm) and may extend into far red. The exact balance of wavelengths is not stated in the title; you would need to read the maker’s specifications or manual to learn more. For many growers, a full spectrum light is a versatile choice for houseplants, seedlings, and general indoor gardening.

How far red appears on grow light listings

Far red can appear in several ways on a listing, and recognizing these phrases helps you compare models without relying on unstated claims. Look for wavelength numbers, diode lists, or stage-specific wording.

• As a specific wavelength number, such as "660nm" or "730nm".
• As part of a diode list, e.g., "Samsung LM301H + 660nm red".
• In the title or bullet points as "far red" or "IR" (infrared, though far red is technically different).
• As a feature for "flowering" or "bloom" stages.
• If the listing does not mention far red, the light likely uses only white LEDs or a standard full spectrum mix. The absence of far red does not mean the light is unsuitable; many plants grow well under white full spectrum light alone.

Comparing far red and standard spectrum on listings

When you compare two listings, one with far red and one without, the main difference is the stated diode composition. A light that lists far red diodes may be marketed for flowering, while a standard full spectrum light is often marketed for all stages. However, the listing itself rarely gives enough detail to know how much far red is present or how it affects the plant.

The DesignLights Consortium (DLC) maintains a Qualified Products List for horticultural lighting that includes tested performance data, but that list does not break down far red content for every model. You can check if a light is on the DLC list as a sign of verified reporting, but the DLC page does not tell you whether far red is beneficial for your specific plants.

In practice, the choice between a light with far red and one without comes down to the information the maker provides. If you grow flowering plants such as tomatoes or peppers, you may consider dimmable LED grow lights that list far red. For general houseplant care, a full spectrum strip light is a practical option.

What to consider for your grow job

Your decision depends on the plants you grow and the amount of detail the listing provides. For houseplants, seedlings, and leafy greens, a standard full spectrum light is commonly used and widely available. For flowering plants, some growers look for lights that include far red, but the listing alone may not confirm a benefit.

The UMN Extension guide explains that all plants need sufficient light for photosynthesis, and that the quality of light (spectrum) can influence plant shape and flowering. However, the guide does not single out far red as a requirement. It recommends matching the plant’s light needs to the available light, whether natural or artificial.

If you are setting up a grow tent for flowering plants, you may see models that list far red as a feature. Compare the stated details: wattage, coverage area, dimming, and timer. The presence of far red is one detail among many. The maker’s page is the place to read how they describe the spectrum. For a 2x2 or 3x3 tent, a quantum board might be a good starting point.

Questions to ask the maker

When a listing mentions far red but does not explain it, you can contact the maker. Here are questions you can ask to get the information you need:

Does the light include dedicated far red LEDs, and what is their wavelength?

How does the maker describe the role of far red for the plants I grow?

Is there a spectrum graph or PPFD map that shows the far red contribution?

Does the light have a separate channel for far red, or is it always on?

The answers to these questions are not part of the listing, so you need to go to the maker’s website or support. This site cannot provide those details. For more guidance on choosing a light, see the best LED grow lights guide.

What to pick for your job

Questions

Is far red necessary for plant growth?

No. Many plants grow well under standard full spectrum light that does not include dedicated far red LEDs. The UMN Extension guide lists light requirements without mentioning far red as a necessity. Some makers include far red as an additional feature, but it is not required for healthy growth.

Does far red help flowering plants?

Some listings market far red for flowering, but this site does not have data to confirm that effect. The maker’s product page may describe a role for far red in flowering. If you grow flowering plants, you can compare lights that list far red against those that do not, and read the maker’s information. For more details, see the best LED grow light panels guide.

Can I use a standard full spectrum light for flowering?

Yes. Standard full spectrum lights cover the red and blue wavelengths that plants use for photosynthesis and flowering. Many growers use full spectrum lights for all stages. The choice between full spectrum and far red depends on the specific model and the maker’s claims.

How can I tell if a light has far red from the listing?

Look for words like "660nm", "730nm", "far red", or "deep red" in the title or bullet points. Some listings also show a spectrum graph in the images. If the listing does not mention these, the light likely does not include dedicated far red LEDs.

Are lights with far red always better?

No. Far red is just one listed feature. Compare the stated details of lights with and without it, such as wattage, coverage, and controls. The maker's page may explain their spectrum design. For most growers, a full spectrum light without far red is a practical choice. See the best LED grow lights guide for selection advice.

Where can I find the maker’s spectrum information?

Visit the maker’s official product page for the model. Look for a specifications tab, a downloadable PDF, or a spectrum graph. The DesignLights Consortium Qualified Products List may also include tested data for some models, but that list does not always break down far red content. For more reading, see understanding full spectrum.