Discussion about factors affecting the purchase of a light
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skunk numba one
Member
If a 315 watt Philips 4200k average PPFD in a 3ftx3ft is 344.48 ; and you put six in a 5ft x 10ft space = 2,066.88?
vs
Gavita 1700e LED: 5ft x 5ft average PPFD: 710 x2 = 1,420
am I getting over 600ppf with the 315's in that grow space?
vs
Gavita 1700e LED: 5ft x 5ft average PPFD: 710 x2 = 1,420
am I getting over 600ppf with the 315's in that grow space?
Result: Did more, sooner. Net result: ~20% more
The 315 is 1.95ppf/w but can't put it all down. Over half must be reflected, with a conservative 10% loss on that portion. This gives at least 5% loss on the total (if only half looses 10%) making it a 1.85ppf/w light (if you are extremely lucky and keep your surfaces spotlessly clean)
LED lights use LED's that might be over 3ppf/w but they also suffer losses. However, with LEDs people tend to of measured the canopy illumination, rather than calculated it. 2.6ppf/w is an easy to reach output for most brands. About 40% more illumination.
You would have to buy some Amazon tat to get an LED that can't beat the CMH in light output. If a move to LED saw no real difference, then the grows limiting factor probably isn't light. This is a real possibility. Many people switched from a 600w 1.7ppf/w sodium to a 315w CMH and did better with less light/heat/spike of a single colour.
It's recent research that's made us aware of the single colour issue. Sodium would knock the colour out of plants, turning areas white, if you let it. All that orange light would excite certain activities, but without the support of other activities, their would be a collapse. The net result of advancing a colour far beyond others, is a net loss. Thus, a sodium light causes significant losses the CMH doesn't. Narrowing the gap between the results of each.
Looking at your figures, a [email protected] should light a meter to 615ppfd in a perfect world. I reasoned a 5% loss, so 585ppfd. A meter is 20% bigger than a 3x3, So 680ppfd would be nice. You say 344? That might get you a DLI of 30 with an 18 hour day, but our figures have slipped somewhere.
Let me look again, 344ppfd over 9 foot. Spread it over 45 foot is 70ppfd. Use 6 of them 420ppfd.
Thing is, if you actually have enough light, then the switch to LED can only really help with lowering temperatures and raising humidity. Plus the obvious power usage and lamp costs. It's not as if your lighting is actually detrimental. You have plant lighting, not street lighting.
The 315 is 1.95ppf/w but can't put it all down. Over half must be reflected, with a conservative 10% loss on that portion. This gives at least 5% loss on the total (if only half looses 10%) making it a 1.85ppf/w light (if you are extremely lucky and keep your surfaces spotlessly clean)
LED lights use LED's that might be over 3ppf/w but they also suffer losses. However, with LEDs people tend to of measured the canopy illumination, rather than calculated it. 2.6ppf/w is an easy to reach output for most brands. About 40% more illumination.
You would have to buy some Amazon tat to get an LED that can't beat the CMH in light output. If a move to LED saw no real difference, then the grows limiting factor probably isn't light. This is a real possibility. Many people switched from a 600w 1.7ppf/w sodium to a 315w CMH and did better with less light/heat/spike of a single colour.
It's recent research that's made us aware of the single colour issue. Sodium would knock the colour out of plants, turning areas white, if you let it. All that orange light would excite certain activities, but without the support of other activities, their would be a collapse. The net result of advancing a colour far beyond others, is a net loss. Thus, a sodium light causes significant losses the CMH doesn't. Narrowing the gap between the results of each.
Looking at your figures, a [email protected] should light a meter to 615ppfd in a perfect world. I reasoned a 5% loss, so 585ppfd. A meter is 20% bigger than a 3x3, So 680ppfd would be nice. You say 344? That might get you a DLI of 30 with an 18 hour day, but our figures have slipped somewhere.
Let me look again, 344ppfd over 9 foot. Spread it over 45 foot is 70ppfd. Use 6 of them 420ppfd.
Thing is, if you actually have enough light, then the switch to LED can only really help with lowering temperatures and raising humidity. Plus the obvious power usage and lamp costs. It's not as if your lighting is actually detrimental. You have plant lighting, not street lighting.
skunk numba one
Member
What is a good number for these plant in PPFD per square foot
Ppfd is already a unit measured per sq meter. U can divide the recomandations to get the sqf value, if you really need it. Also, how much plants needs depends on environment, genetics, and how good of a feed it receives. Around 1200 ppfd i see used a lot, good number for home growers, maybe up to 1500-1800 ppfd in some comercial applications. Around 2000 is where it gets to be too much no matter how good of a grower you are and how good of an environment you keep..
skunk numba one
Member
ppfd is measured in square meter so why do charts show a 5ft x 5ft area with 100 readings? 5ft x 5ft = 2.3m2
you might see 1200 ppfd at the center of the light but never the average reading over 5ft x 5ft.
skunk numba one
Member
Ok. I guess we should stop using leds?
It depends on the light and hanging distance, but I am pretty sure you can get to 1200 ppfd+ with most comercial led lights. You here to bash leds or to learn using them, tho?
this is just a discussion about factors affecting the purchase of a light
I look at Migro youtube videos on real world PAR readings:
Mammoth 8 bar 800W LED Grow Light & 100W UVA & UVB LED bars: average 863 umol/m2/s over 5ft x 5ft
HLG Scorpio Diablo: average 792 umol/m2/s over 5ft x 5ft
Gavita 1700e: 710 umol/m2/s over 5ft x 5ft
Does somebody have some actual real world bud results? What i find the same about LED is they are always promoted by people selling them. They like to throw around all these fancy terms of light,, color, cost over time. None that shit matters if you cant grow big juicy buds.
Dont get me wrong i have seen some successes with LED. But i still haven’t seen is a smoking gun comparison. HPS bud continues to be bigger fstter, more dense and subsequently higher quality.
LED tech to me is like electric cars. Sounds good, looks good. But falls short on performance.
Show
Show me buds like these?? These are mine grown under a 1000w horitux. HPS.
Show me comparable sized nugs with LED?? Thats all im asking. Its not about cost for me. I will go out and buy the next best thing if it can walk the talk.. i haven’t seen it. The cost to me is in the product produced.
Mind you i have taken almost a 8 year hiatus from growing. The talk hasent changed that much with LED. We do have better tech.. but can it grow big dank like HPS. Everytime i have asked. More talk.
Dont get me wrong i have seen some successes with LED. But i still haven’t seen is a smoking gun comparison. HPS bud continues to be bigger fstter, more dense and subsequently higher quality.
LED tech to me is like electric cars. Sounds good, looks good. But falls short on performance.
Show
Show me buds like these?? These are mine grown under a 1000w horitux. HPS.
Show me comparable sized nugs with LED?? Thats all im asking. Its not about cost for me. I will go out and buy the next best thing if it can walk the talk.. i haven’t seen it. The cost to me is in the product produced.
Mind you i have taken almost a 8 year hiatus from growing. The talk hasent changed that much with LED. We do have better tech.. but can it grow big dank like HPS. Everytime i have asked. More talk.
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There are some nice fat grows on here that are partly or mostly leds. Myself I am just learning, but for sure I have better results than before, with hps. I don't feel the buds grown under leds are lacking in any way, but also know ita a diferent tech and needs to be used to its advantages, not taken for granted and used as a hps would be, expect it to just give better results..
Three Berries
Active member
They need to come up with a revolving light mount so the lights cover everything.
skunk numba one
Member
1000w DE HPS wouldn't have the ceiling height in a grow tent and the commercial growers that can use those lights don't share very much info unless you are in their circle.
heat can be delt with. And if nobody is sharing results then what leg do they have exactly? These were grown in a 4X5X7 space with a vented hood. Heat can be midigated.
Every time i have posted my dank and invited the pro LED group to challenge size density, qaulity. They dont. I was hoping to see more results in my 8 year break. Now all we have is youtube stars sharing a bunch of light terminology jargon.
Every time i have posted my dank and invited the pro LED group to challenge size density, qaulity. They dont. I was hoping to see more results in my 8 year break. Now all we have is youtube stars sharing a bunch of light terminology jargon.
skunk numba one
Member
those must be single ended HPS? They don't even make those for sell anymore.
Yes they do. Those are both brand new 600w HPS . Lol
I might do some playing with DE and CMH bulbs, in the future. but based on current information. LED isnt on the table, which is slightly disappointing to be honest. I will set a base line first in the new show . Then compare.
I might do some playing with DE and CMH bulbs, in the future. but based on current information. LED isnt on the table, which is slightly disappointing to be honest. I will set a base line first in the new show . Then compare.
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There is no shortage of those bulbs bud. Hortilux is still pumping them outs DE bulbs arnt going anywhere either. I was actually hoping to see some LED results that would convince me. Nothing so far.
HID does grow bigger buds, if looked at individually. The pic I shared shows this. The problem is how far apart those bigger buds are. HID causes more elongated plants, as the main leads become dominant. The side branching loosing out. These dominant leads, with 360 lighting, grow dominant buds. The gaps left from less branching give the appearance of a deeper canopy. Giving these big long buds that the LED virgin doesn't realise are miles apart. The LED grower gets a scrog like grow. No dominant leads of the same magnitude. Lots of stronger side branching though. LED grows smaller buds, but in greater quantity.
There is no major difference in product. LED plants taste more, and the buds are actually denser. Linked to the fact they are more compact plants, that didn't get baked off.
PPFD is a measure of how many protons are present. We are counting photons. When the idea of counting them was devised, they had to decide how big a space to count them within. They could of said, how many photons are hitting a pin-head per second. That could of worked, if a pin-head was a SI unit. We could of manufactured our photon counter, that might of been bigger than a pin-head, and had it work out what it would of counted had it been pin-head sized.
Instead, we chose a meter. No matter how big your light meter is, it's talking about how many photons fall upon an entire meter, if the entire meter was illuminated to that level.
Metric is good. People that don't use it, spend all their time converting back and forth without seeing it's elegance. If a lamp gives off 1000 ppf, and they all fall on a meter, that meter is 1000 ppfd. There is no maths.
Sticking with an outdated measurement system? Then you are not trying to move forward. It's a self imposed handicap. Science is Metric.
There is no major difference in product. LED plants taste more, and the buds are actually denser. Linked to the fact they are more compact plants, that didn't get baked off.
PPFD is a measure of how many protons are present. We are counting photons. When the idea of counting them was devised, they had to decide how big a space to count them within. They could of said, how many photons are hitting a pin-head per second. That could of worked, if a pin-head was a SI unit. We could of manufactured our photon counter, that might of been bigger than a pin-head, and had it work out what it would of counted had it been pin-head sized.
Instead, we chose a meter. No matter how big your light meter is, it's talking about how many photons fall upon an entire meter, if the entire meter was illuminated to that level.
Metric is good. People that don't use it, spend all their time converting back and forth without seeing it's elegance. If a lamp gives off 1000 ppf, and they all fall on a meter, that meter is 1000 ppfd. There is no maths.
Sticking with an outdated measurement system? Then you are not trying to move forward. It's a self imposed handicap. Science is Metric.
Sante
In DoPa
Surely lifespan(i mean keeping a good efficiency over the years), and possibility of fix any issue fast and cheap and on my own,
after that cost/watt, par/watt, quality of components(heatsink, driver) and light diffusion..surely new smd boards and bars are not my cup of tea for more than one point above.
Sorry for my eng.
after that cost/watt, par/watt, quality of components(heatsink, driver) and light diffusion..surely new smd boards and bars are not my cup of tea for more than one point above.
Sorry for my eng.
skunk numba one
Member
