Is PAR Just Another Gimmick?
- Thread starter FNG Grower
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Rahz
Well-Known Member
Par is a measure of photons in the 400-700nm range. PAR is not weighted but the McCree curve shows plants will take and use whatever they can get.
I digitized the McCree curve years ago for 5 different spectrums at the same wattage and when the curve was applied it modified the numbers but not in a crazy way. I didn't digitize blurple but it would show some gains -vs- white with a "McCree factor" applied, given the same input. Whether that translates into more growth isn't as straight forward.
PAR isn't perfect but somewhat better than Lumens. PPFD better than LUX. That being said, a LUX meter isn't a terrible way to measure light intensity under plants. There are various ways to quantify light quantity/intensity. Even watts wasn't terrible but with the advent of LED measurement in watts becomes suspicious because the efficiency can be all over the place.
I would prefer to know PAR of a lamp, assuming the rating is honest.
Rocket Soul
Well-Known Member
Yes par might be bullshit in the case of a growlight that has super high par but nothing in mentioned nm. However, can you give one example of such a light? Full par but no reds no blues in any shape? Until you actually find one par is going to be quite relevant.
These plants exhibit pretty much all of the characteristics of plants that have received very little light.
They are extremely tall, have significant internodal space, and have very little foliage.
The plant in the photo below has the opposite characteristics. A significant factor is that it was topped and LST'd. It measures 30" across, 28" front to back, and is about 24" tall. The branches are up to 36" long and the foliage is dense. The plant was grown using high light levels, at least 300µmol in seedling (24/0 photoperiod) and then moved to an average of over 850µmol across the canopy.
This is a typical autoflower grow. Feed it lots of light and they grow…through the roof. Cannabis thrives in ambient CO2 at up to about 1000µmol. More photons = more food = more flower.
I have an Apogee and a Uni-T for lux meters. I've tested Photone twice and, based on the outcome and after having traded email with their programmer, I only recommend it in specific circumstances (I've been a software engineer for over 30 years so I have some insight into the issues that they're dealing with).
Though I prefer to use the Apogee, it's expensive and if I were starting over again, I wouldn't get one. I'd but the Uni-T Bluetooth and do the math. I've attached a PDF that provides some insight into Lux vs PPFD and how to convert to PPFD.
My argument - for most personal grower situations, the Uni-T Bluetooth lux meter is the weapon of choice. The reading from the Uni-T is, in practical terms, as accurate that the readings you'll get from an Apogee. Neither instrument will ensure a great crop — a fool with a tool is still a fool. However, a lux meter allows you to get your grow to a higher level of light more quickly, it reduces the chances of damaging the leaves on the plant, and it allows you to determine how even the light cast is on your canopy which allows the grower to make informed decisions about how to light their grow and how to shape their plants. The human eye is biologically incapable of perceiving even major variances in PAR so any decisions made by the Mark IV eyeball cannot have a factual basis.
There's no argument about what a grower "needs" - that's a straw man argument offered either mistakenly or disingenuously. For the sake of $32 and taking some time to learn, a grower can significantly increase the yield and quality of their grow (quality being the ratio of flower to total plant mass). Many grows that I see would increase yield by at least 50%; some would increase 100% (double). And all you have to do is read the light meter and turn up the dial.
Howzat? - it's because with cannabis, research repeatedly demonstrates that crop yield increases in an almost linear manner as light levels increase. A light meter is a cheap way to for a grower to consistently get a much better outcome.
i know, the photo is when i just switched to 2x8 bulbs, they got to that stage with only 112 watts (so 8 bulbs) and i added 16 more when i switched to flower, see this was like an experiment, now i know household bulbs can grow something and do pretty good, do not miss my next update on the grow diary secction, now they are sitting under 326 and getting fat, and you see when they where young and the light (8x 14w bulbs) was sitting close (12 inches) i got some of the shortest internodals ever growing and got 9 plants to show sex in a 2x3 in 4 weeks using only 120 watts, so i was aiming for what i got, i agree that yours is way better and professional but hey i wanted to grow something in the closet care free and only watering each 2 days,, this is not my first grow, i have grown using the finest leds and hps ligts, i even laid my hands on a 400v dimable hps system, but this time i wanted to do a budget grow i only spent like 150 bucks on everything, and i could not have cared less for the plants haha i would say you spent more for that pretty humidifier
and... is that a sp3000 used for side lighting? lol i used to have one, pretty good light, it does not get hot and the plants love it, i loved that light
i used it with a 600 hps and got some fire flower;
oh and my plants where topped and lst ed too even a litle hst there on the top with the supercropping of the mains
i think the intermodals are aok you will see now with more light it will fill that space with bud
btw hey i love your hydroponic system you got some nice trees there , one question, are you forced to leave the door open on that 2x4? (now that i think about it its pretty obvius with side lighting you leave it open, then whats the need of the grow tent? could just line the walls with mylar xd)
bless
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Great info. Thanks for posting it and explaining "the method being the madness".i know, the photo is when i just switched to 2x8 bulbs, they got to that stage with only 112 watts (so 8 bulbs) and i added 16 more when i switched to flower, see this was like an experiment, now i know household bulbs can grow something and do pretty good, do not miss my next update on the grow diary secction, now they are sitting under 326 and getting fat, and you see when they where young and the light (8x 14w bulbs) was sitting close (12 inches) i got some of the shortest internodals ever growing and got 9 plants to show sex in a 2x3 in 4 weeks using only 120 watts, so i was aiming for what i got, i agree that yours is way better and professional but hey i wanted to grow something in the closet care free and only watering each 2 days,, this is not my first grow, i have grown using the finest leds and hps ligts, i even laid my hands on a 400v dimable hps system, but this time i wanted to do a budget grow i only spent like 150 bucks on everything, and i could not have cared less for the plants haha i would say you spent more for that pretty humidifier
I'm glad that the plants started filling out after you got more light on them. "Cannabis is
"pretty humidifier" - Good eye. That's an AC Infinity humidifier and there's a Controller 69 in the tent. Doing the math and you're right on target - $150±. Worth every penny because it keeps VPD where I set it and that means fewer trips into the tent which means less disturbance of the environment.
There's another thread here on RIU about how much money we've spent on our grow environment. That's not a curtain I want to look behind!
Seriously, though, I don't mind the $$ because it's cost effective for me. I write software and bill by the hour so it costs me money to futz with things. I had a PulseOne + Inkbird + a different humidifier and I spent quite a bit of time keeping VPD in range. All of that got replaced by the Controller 69 + their humidifier and I retired the old equipment. That saved me quite a few hours over the course of the grow. I also got more cannabis and, seeing that prices in SoCal are insane for legal weed, the numbers work out. If I lived in Colorado or somewhere where weed is cheap, I wouldn't be growing my own but here in the People's Republic, things are different in a lot of ways.
The Mars was my first light in 2021. I did a grow in 2017 using a Kind blurple and then archived everything. When I started growing again, I picked the Mars because it was a single bar light, so it was easy to work with, and it's got a really good PPFD map. It's not a "sexy" light like the bar lights and the other two SP's just don't have a lot going for them but the 3k is nice. After using it for a couple of grows, I decided to go with separate veg and flower Growcrafts and it's worked out well. I'm getting better quality plants with the two lights but that's not a knock on the Mars. I think it's a very cost effective light.
What did you do with your SP 3000?
Yeh, HPS is great for flower. After a couple of grows with the mars, I read/learned enough about grow lighting to decide to go with separate veg and flower lights. I didn't want to do incandescent light so I ended up with the Growcraft lights. They each have a spectrum to MH and HPS, respectively, but more photons and less heat which is nice since electricity is 40¢, give or take, per KwH and it can get pretty warm here. The spectrum for the Growcraft flower light has a ton of red so I'm getting good yields, similar to HPS.
Good. I hope they fill in. They didn't get much food as kids but make up for them now that they're teenagers.
You nailed it. That was an auto and you know they have a mind of their own. I could have trimmed it back, sure, but it made more to just leave the tent open, try to keep things upright, and use the lights that I already had.
Autos aren't really worth it with a big bucket like that. That's my "history-major brain" + five auto grows of knowledge thinking. With nothing to restrict the size of the rootball, they just keep growing and growing and growing so I ended up with a 110 + day grows. Lotsa weed but run >=400 watts 18/6 to 20/4 for 110 days at 40¢ per KwH, having to jump through hoops all the while. IIRC, that was one of two grows that got hit by thrips.
It's much easier to run photos. It saves on labor and electricity, and I think I'll end up with pretty much the same harvest.
I was growing like 5 plants under the sp 3000 and they got side hps lighting (from 9 plants sitting under the hps) and it was fire growth, super lush green and no sign of light searching at all, now coming back to my current grow, the first foto, hehe i know they where ugly in that stage, as i told you they just got upgraded with 16 bulbs for 3 days before that foto and then 24 bulbs from week 2 of flower so yeah.. ideally i would have upped the light day one flower, but i didn't have the money to buy it in time i only wanted to show what you can do with only 8 bulbs which is all they got as babies for 5 weeks.
Here you can see a little the short intermodals, with the light at 18 inches , in this foto they are not so short anymore, I began raising the light like 2 weeks prior because they where still 4plants (one male wich had not shown sex yet) so they where even shorter when the light was sitting at 12 inches for 9 solo cups.
and now they are at the end of week 3 of flower, stretch totally stopped and they are focusing on getting fat; keep in mind that the lights of this foto were just added so to see the results we will come back next week, what you are seeing is 1 week of only 24 14w bulbs, today i added 3x 20w 2700k Philips phosphorescent bulbs and a 35w 6500k led bulb ( only trying it is for the veg side) i got enough blue with the 3000 4000 and 4500k that are mixed in, and now i got some more reds, far reds + some ir from the phosphors
the two on the sides got deficiencies, the one on the right, n def nothing too crazy
but the girl on the left... she's got calcium/magnesium def and maybe phosphorous too, i think i overwatered her giving her the same as the other two, may be a airflow to the back problem, she is the furthest away from the intake i will troubleshoot that problem.
i also want to build a veg dedicated space
building this for the veg side
they are smd 2835 6400k , with thin aluminum radiator and with their own 20w mains driver for 5 bucks each
they give off 2100lm and i have 3 of them, i will do like a bar fixture with them and hopefully veg a 2x2 space with 60w total
if you want to see more fotos here is a link to the journal;
i only wanted to show what you can do with only 8 bulbs which is all they got as babies for 5 weeks.Here you can see a little the short intermodals, with the light at 18 inches , in this foto they are not so short anymore, I began raising the light like 2 weeks prior because they where still 4plants (one male wich had not shown sex yet) so they where even shorter when the light was sitting at 12 inches for 9 solo cups.
and now they are at the end of week 3 of flower, stretch totally stopped and they are focusing on getting fat; keep in mind that the lights of this foto were just added so to see the results we will come back next week, what you are seeing is 1 week of only 24 14w bulbs, today i added 3x 20w 2700k Philips phosphorescent bulbs and a 35w 6500k led bulb ( only trying it is for the veg side) i got enough blue with the 3000 4000 and 4500k that are mixed in, and now i got some more reds, far reds + some ir from the phosphors
the two on the sides got deficiencies, the one on the right, n def nothing too crazy
but the girl on the left... she's got calcium/magnesium def and maybe phosphorous too, i think i overwatered her giving her the same as the other two, may be a airflow to the back problem, she is the furthest away from the intake i will troubleshoot that problem.
i also want to build a veg dedicated space
building this for the veg side
they are smd 2835 6400k , with thin aluminum radiator and with their own 20w mains driver for 5 bucks each
they give off 2100lm and i have 3 of them, i will do like a bar fixture with them and hopefully veg a 2x2 space with 60w total
if you want to see more fotos here is a link to the journal;
m1100 grow in a 2x3 DIY led cabinet
Here i show you my grow op in my room cabinet. the space is 60x90cm or 3x2 Got rid of the bulky heater fan (i was using only fan) and threw in a couple brushless 12v fans. I did the lights , they are 6x 14w regular 4000-4500k e27 led + 2x 17w 6500k. The cabinet is painted white. The...
www.rollitup.org
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Have2
Well-Known Member
i'd be curious to compare the pulse pro spectrum reading to some high price spectrum meter out there.not much to tell you hold it under your light near the canopy and it gives a measurement of the light intensity ive been using that to dial in the height of light so i can get maximum light at the canopy without burning the plants in a co2 enriched room. better than guessing with the back of my hand and hps light
Quantum Sensors - PAR Meters | Apogee Instruments
Apogee Instruments’ quantum sensors are the tool of choice for researchers and agricultural professionals measuring photosynthetically active radiation (PAR) and daily light integral all over the world.www.apogeeinstruments.com
i also got a pulse pro that measures spectrum but i cant speak for how accurate that is.
Pulse Pro
The Pulse Pro offers enhanced grow room monitoring with CO2, PPFD/PAR, light spectrum, vapor pressure deficit, temperature, and humidity tracking. This advanced monitor boasts real-time and historical data, customizable alerts, and support for multiple sensors and WiFi networks. Crafted in the...pulsegrow.com
Anyone can chime in on this? it would be really interesting !
Tbh i wouldn't expect too much from it at that price. A hygrometer costs around 10 $, a co2 meter starts at 60 $ (but those are really bad), a quantum meter is in the range of 300 $ and a simple spectrometer is atleast 4 digits but the sky is the limit.
Proper calibration easily doubles the cost of each sensor.
Also they don't give any performance characteristics of the spectrometer compoment. The other sensors atleast has a measurement uncertainty attached (but no information how that was derived).
Have2
Well-Known Member
That's also my though but still curious!
Send them an email about what sensors they use. I have a PulseOne and they publish the manufacturer and model number for some of the components. Perhaps they'll do the same for the Pro.