All factors need to be used in combination to select the most appropriate systems based on your cultivation and business goals, and the take home message is that PPF, PPFD, and photon efficiency are the proper metrics used by scientists and industry leading horticulture lighting companies. If a company does not provide you with the correct metrics used for horticulture lighting, they should not be selling horticulture lighting systems, and you will not be able to verify the true efficacy of their system.
Your evaluation and final choice depend on many factors:
◽ your grow environment (for example: temperature, humidity, air circulation, background noise, heat etc.)
◽ the strain you are growing (strains react differently on different types of lighting, techniques etc.)
◽ your (personal) growing technique (are you using the ''SCROG'', ''SOG'' or an other method/technique ?)
◽ your personal health (for example: does your health allow you to work on your knees, to bend, to ''SCROG'' ?)
◽ your goal (are you growing seedlings, cuttings, mother plants; do the crops remain in the vegetative phase, or do they bloom as well ?)
There are multiple considerations that a consumer or business faces when evaluating light sources to use for horticultural lighting:
◽ PAR, PPF, PPFD measurements ?
◽ What is the photon efficiency ( μmol/J) ?
◽ Is the spectrum tuned for the application ? Is the spectrum adjustable or fixed?
◽ How is the uniformity of light distribution ?
◽ What is the fixture lifespan ? How many years of warranty ?
◽ What is the process for spare parts and repairs ?
◽ Does the fixture have adjustable power ?
◽ Which LED brand and diode is used? (Nichia (Japan), Osram (Germany), CREE (USA), Showa Denko (Japan), Philips (Netherlands), Toyoda Gosei (Japan), Citizen Electronics (Japan), Epistar (Taiwan), GeneLite + Genesis Photonics (Japan + Taiwan), Luxeon (Canada), Bridgelux (China), Epileds (China) etc.)
◽ Which LEDs are used, COB or normal ? Any special optics used?
◽ Can multiple fixtures be connected together ?
◽ What are the main benefits for the specific technology ? Any special features used ?
The Fundamentals of Light - Nick Klase