FAQ'S

Questions? Leave it to us to provide the answers!

What can I grow with Curtis Mathes Harvester® lighting?

Anything! Due to our full spectrum output and efficient photon delivery, growing with our lights is highly effective for every plant we have come across. This includes cannabis, hemp, roses, orchids, vegetables, herbs, spices, carnivorous plants – anything!

How many lights will I need?

This depends upon your crop type, footprint (grow area), and stage of growth.

Lighting a crop is a three-step process:

  1. Provide the correct Spectrum (which we do),
  2. Cover your crop, and,
  3. Add lights to reach your desired yield.

While we are more than happy to tailor a lighting solution for any size grow and any plant at any stage of growth, we can provide a general rule-of-thumb for certain crops.  For hemp and cannabis cultivation, we suggest 205W-410W (1x-2x Harvester® modules) per 25ft2 for vegetative stages and 615W-1025W (3x-5x Harvester® modules) per 25ft2 for flowering stages of growth.  For choice of lighting during flowering, you’ll need to consider plant genetics, plant densities and grow methods to determine the amount of light necessary to produce the highest yield.  Call us – we are glad to help with this!

Lighting a crop is a three-step process:
1. Provide the correct Spectrum (which we do),
2. Cover your crop, and,
2. Add lights to reach your desired yield

How do I determine yield capabilities?

It is very important to keep in mind that lighting sets the POTENTIAL for your crop –  potential for yield and for quality.

There are hundreds of variables that must be monitored and adjusted to produce the highest crop yields and quality.

New growers following some simple instructions routinely achieve 1 gram of dried flower per Watt of lighting power used (cannabis). Some of our customers are boasting 2gms/W.  See the section in this FAQ titled “How many lights will I need?” and feel free to call or email us at growhelp@cmgrowlights.com.

"My plants look like they are burning, help!"
There is almost no way heat produced by our lighting is burning your plants. It is most likely that your plants are “bleaching”. This bleaching is commonly known as ‘cotton-top’ and is caused by underfeeding your plants. Our full spectrum output activates many more plant photo-receptors than non-full-spectrum lighting. This causes plants to process more nutrients, CO2 and water. If you don’t provide enough nutrients to satisfy your plant’s newfound hunger, it shows in the form of this ‘cotton-top’ effect. In most cases, increasing nutrient availability will solve this issue.
Have your lights been tested?

Yes. After we design and test our lights in operational grows, we sent them off to CSA labs, a lighting industry standard testing service. We have a full spectral analysis performed and a lighting distribution map created. The resulting report and *.ies files that are created allow us to plug the results into lighting software in order to run power, distribution and intensity calculations for any indoor or outdoor grow operation. We provide results to you that assist with best use of lighting, power and thermal management/HVAC requirements.

In addition, our lights are certified by ETL to UL Standard 1598:2018 Ed.4, CSA C22.2#250.0:2018 Ed.4, all per Horticultural Luminaire as defined in the Outline of Investigation For Horticultural Lighting Equipment [UL SUBJECT 8800: 2017 Ed. 1].

How should I mount my lights?

This is a matter of preference. Some people choose to mount their LED grow lights with hooks, chains, string, etc. A popular solution is to use “yo-yo’s” made from rope or wire that will support the weight of the Harvester®. We include yo-yo’s with every light purchased.  For multiple Harvester® modules, we make 2 frame options to group the modules in efficient arrays.

Can I combine your lights with HPS?

Absolutely! Many customers in colder climates choose to place a small HID lamp in with our LEDs in order to generate a bit of heat. Use of this small HID lamp, in addition to providing additional light to your plants, usually saves a lot of money vs. using a space heater, or heating a whole room.

How many lumens do your lights put out?

Our Harvester® is a highly configurable system built upon 205W lighting modules. Each 205W module emits about 22,100 lumens. However, using lumens as a measure of horticultural lighting effectiveness is highly misleading. The true measure of horticultural lighting potential begins with Yield Photosynthetic Photon Flux (YPPF). You may have heard of Photosynthetic Photon Flux (PPF), but YPPF is coming more into use as it observes spectrum outside human vision limits. PPF = 400-700nm and YPPF = 380-780nm.

 

Determination of YPPF is a complex application of photosynthetic effectiveness mapped to every frequency in the visible spectrum, and beyond. While YPPF ranges vary depending upon who you ask, we use the effective range of 380nm-780nm. The limits of human vision are from 400nm to 700nm, but plants “see” much more than the human eye, often using frequencies far outside our range of vision for various photobiological functions.

 

To take this a step further, it is important to note that we must observe the total spectrum output of a light, not just the numbers thrown around in spec sheets. For example, 100W of 550nm pure green light will produce a much higher YPPF than 100W of full spectrum lighting. However, the quality of plants grown under the full spectrum lighting will be far superior in nutrients and other phytochemical (phyto=plant) production, and the yields much bigger.

Are your lights "Made in the USA"?

No. We manufacture in a medium-sized specialty lighting manufacturing plant in China, separate from the manufacturing plants that make most of the other lights you can find on the Internet. We have a partner on the ground in China – a trained opto-electronics engineer with a Master’s Degree that has been our partner for over 15 years. He oversees logistics, manufacturing and quality control. Fifteen years ago, buying LEDs in China was not advised. Now, there are very few, if any, US-made LEDs. Even the heavy-hitter’s now manufacture offshore. For example, Bridgelux, a US company and lead in horticultural LEDs, was purchased by the China-Government-owned Kaistar Company.

 

Beware companies claiming their products are “Made in USA”. The Federal Trade Commission (FTC) outlines and enforces very strict guidelines concerning claims of “Made in USA”. As almost no high end LEDs are made in the USA any longer, and most aluminum products cost a fraction offshore vs “Made in USA” aluminum. The end-result is that the “Made in USA” claims you see are likely false.

What kind of LEDs do you use?

We primarily use GM and Edison Optoelectronics LEDs. We have used Cree, Bridgelux, Lumileds and Nichia in the past. We have been using these LEDs for over a decade with outstanding results in horticultural applications, with extremely low failure rates. GM now produces a proprietary LED for us.  It is a blue-pumped phosphor coated diode built to our exact spectrum requirements. 

Can LED grow lights damage your eyes?

Absolutely. Any bright light source can damage your retinas, but blue light is especially harmful and the “bluer” it gets, the more potential for damage – especially ultraviolet light. Blue light is shorter in wavelength and therefore, much more powerful than green/amber/red light.

Today’s white LEDs are made with high-powered blue LEDs coated in a special phosphor. The blue output causes the phosphor coating to fluoresce – producing light across the visible spectrum, which appears white to the human eye. Studies suggest that continued exposure to blue light over time could lead to damaged retinal cells. This can cause vision problems like age-related macular degeneration.

Source: https://www.preventblindness.org › blue-light-and-your-eyes

What is your failure rate?

Less than 1/10 of 1% (0.001). We attribute these stellar rates to our sources of supply, our manufacturing process, the fact that we burn-in test EACH AND EVERY light for 3 days straight, and most of all, to our superior thermal management design and lack of cooling fans (fans break…a lot).

Are your lights "broad" or "full" spectrum?

Our lights are truly full spectrum, meaning, we provide photons in absolutely every frequency across the visible spectrum – and even into the near-infrared range.

Some manufacturers and vendors use “broad” and “full” interchangeably, but beware – they are not the same.

While providing light in 5 – 11 different frequencies may be considered broad, there are a lot of holes between these frequencies.

You will see many claims that only a few frequencies corresponding to the Chlorophyll A and B absorption peaks are all that are necessary to grow plants. NOT TRUE. In over 10 years of grow light development, we have proven in our labs and for 1,000’s of customers that plants thrive in TRUE full spectrum grow lighting. It is scientifically well-documented that most plants can use the entire spectrum for photosynthesis. Some vendors rationalize their position (using only red and blue lights) by stating that plants are green because they don’t absorb ANY light in the green range. Again, NOT TRUE. The reason we see many plants as green is that plants do not absorb AS MUCH light in this frequency range, and that the difference between a plant’s ability to absorb (for example) red light and green light is as little as 3%-5%. The result – more green light is reflected than red, and we observe this reflected light (and plants) as green (550nm is pure green).

How does the warranty work?

Curtis Mathes Grow Lights, Inc. warrants that this product shall be free of defects in material and workmanship for five (5) years from date of purchase. If there is such a defect, we will repair or replace the Product as appropriate and as determined by Curtis Mathes Grow Lights, Inc. For more warranty information, click here.

Curtis Mathes Grow Lights, Inc. (CURTIS MATHES) warrants that the Harvester® product shall be free of defects in material and workmanship for 5 years from purchase. In case of defect, CURTIS MATHES will repair or replace the Product as appropriate and as determined by CURTIS MATHES.

Purchaser must notify CURTIS MATHES of the defect before the warranty expiration date(s). The CURTIS MATHES corporate or distribution office will advise the Purchaser of the nearest service address to which the Purchaser must ship the defective product at his/her own expense. The product should be packed safely, in the original (or comparable) packaging. CURTIS MATHES will pay return shipping costs to the customer once the Product is repaired or replaced. Shipments received not in compliance with the terms of this warranty will be shipped back to Purchaser, at Purchaser’s expense.

This warranty applies only to the hardware specified on this page and used normally within its operating specifications. It does not cover hardware modified in any way, or subject to unusual physical, electrical or environmental stress, including water damage, or acts of nature, or if used in an incorrectly installed manner, or with the original identification marks altered. This warranty is valid for the original Purchaser only.

CURTIS MATHES neither assumes nor authorizes any person to assume on its behalf any liability in connection with the sale, installation, service or use of its products. CURTIS MATHES shall not be held responsible for special, consequential or punitive damages of any kind arising out of sale, installation service or use of their products. CURTIS MATHES does not warrant that Product is suitable for any specific purpose. Mounting hardware is not covered by this warranty.

The Purchaser is entitled to free technical support for any CURTIS MATHES product for the warranty period. Technical support includes advice concerning installation and operation of CURTIS MATHES products.

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