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 2×4 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
