Cannabis Grow Lights Guide: How Many Watts? What is PAR? PPFD? Cannabis Grow-Lights Crash Course!

Watch this BEFORE you buy cannabis grow lights! We explain PAR, PPFD, PPF, DLI, Lumens,Watts, PAR Charts, LUX, Spectrum & more Two Mars Hydro SP 3000 Grow Lights Used in our Grow (in two 2x4 grow tents) [0:00] WHY THIS VIDEO? Buying Grow Lights for Cannabis is Complicated. At GrowDaddyTV Studios we have a pair of Mars-Hydro SP-3000. We hope you find this video useful - GrowDaddy has found the jargon and physics involved in the lighting market to be overly complicated and confusing. He even bought blurple lights and a lux meter when they were the WRONG tools for the job! This is the third light setup so far - so we've learned a lot from past mistakes. [0:42] WATTAGE - RULES OF THUMB • 30 watts per square meter for white and red LEDs (premium lights) • 35 watts per square meter for white LEDs • 50 watts per square meter for high-pressure sodium lights • 100 watts per square meter for fluorescent lights [1:55] TERMINOLOGY: PPFD, PPF, PAR, LUX METERS, FOOT CANDLES • PPFD = Photosynthetic Photon Flux Density • PPF = Photosynthetic Photon Flux • PAR = Photosynthetic Active Radiation • LUX = lux is a unit of illumination (light visible to the human eye – NOT relevant to growing) • LUX METER = a device that measured the lux in an area – it’s in metric. • FOOT CANDLES = Like a LUX METER but the measurement of lux is in imperial as opposed to metric [2:50] Do not buy a LUX METER There is a rant here. Lux is a unit of measurement for light which is visible for the human eye. Lux is not useful for horticulture, and don't get bamboozled into buying a lux meter! [3:54] PPFD / PAR Requirements at Different Stages of Growth • SEEDLINGS / CLONES: 100 – 300 PPFD • VEG STAGE: 250 – 600 PPFD • FLOWER: 500 – 1050 PPFD [5:44] DECODING PAR CHARTS PPFD / PAR CHARTS - Take manufacturer’s PPFD / PAR charts with a grain of salt. They are putting their best foot forward and their findings don't really reflect real world PAR in a grow tent full of plants. It's very important to go and find some independent reviews of lights if you are planning to buy them. [6:08] Mars-Hydro SP-3000 PAR Chart • SP-3000 – Draws 300 WATTS - This is GrowDaddy's light! [7:58] • TSL-2000 – Also draws 300 WATTS - This is the "budget version" of GrowDaddy's grow light [10:49] BLEED OVER What is “bleedover” on your lights? You can actually use two or more smaller lights in your tent to get great coverage of the entire canopy. [11:52] D.L.I. = Daily Light Integral DLI in a nutshell measures how much light delivered to a specific area over a 24-hour period. The PAR meter measures the light per second and DLI is the total "daytime" (or lights-on-period) light. Autoflowers and photoperiods have different PAR requirements because the photoperiod flowers only have their lights on for 12 hours, whereas autos have their lights on for 18+ hours at a time. [13:18] SPECTRUM Spectrum of these grow lights is NOT A BIG DEAL – it's mostly marketing. Flowers don’t care much about the spectrum. In veg, spectrum may have some effect but no big deal. In flower, spectrum has no effect at all. [11:52] DLI = Daily Light Integral – 900 PAR FOR FLOWERS MAX AUTOs Vs PHOTOs This is another way to measure the light requirement. It’s a geeky way of getting even more confused. It’s great if you want to know more, and can help you shop for lights. [16:21] SUMMARY: How to Buy Grow Lights for Cannabis (for Stoners) • First decide what kind of lights you want – LED, HPS, Flourescents • Next calculate your watts needed for the tent size • Remember PAR, PPFD & PPF are basically the same thing • Do NOT BUY a Lux Meter • Remember different stages of growth need different amounts of light • I’ve shown you PAR charts – do NOT go by Manufacturers’ Charts! We use a PHOTOBIO PAR Meter: https://www.amazon.ca/PHOTOBIO-LGBQM2-Advanced-Quantum-Micromols/dp/B08HPGLZHL/ref=sr_1_1?crid=2IPEMLQWFRRUT&keywords=PHOTOBIO+Advanced+Quantum+PAR+Meter&qid=1653009576&sprefix=photobio+advanced+quantum+par+meter%252Caps%252C255&sr=8-1&_encoding=UTF8&tag=netgenuscom-20&linkCode=ur2&linkId=6a13e14af759a17a16304b26f9a09d33&camp=15121&creative=330641 I don’t want you to believe me. I want you to go and learn from professionals, not from stoners! I’m just pointing you in the right direction. I want you to learn from: • Dr. Bruce Bugbee AKA Professor Bruce Bugbee - Utah State University: Does experiments / demonstrations / debunks Bro Science Plants in space – he’s a kind of a big deal https://www.youtube.com/c/Apogeeinstrumentsincorporated • Shane at MiGRO: https://www.youtube.com/c/MIGROLIGHT They are experts and they disprove a lot of Bro Science like the green spectrum not being seen by plants. [21:15] SILLY OUTRO / BLOOPERS "Pie charts" vs. "PAR charts." & "Photosynthesis" #cannabiseducation #cannabisgrower #growlights #growmarijuana