[Harborseal]

This helps it explain the useful portion of the light spectrum

another good link
http://homeguides.sfgate.com/plant-l...nts-72801.html

This curve above is the chlorophyll absorbtion curve. What you really want is the photosynthetic absorbtion curve. That measures energy output vs wavelength of light input. That's here:

photosynthetically active spectrum




You can see that plants can use wavelengths in the middle of the spectrum. This is because there are other pigments besides Chlorophyll that can share electrons with it. These are the pigments that show up in the fall as the chlorophyll decays.

Also note that wavelengths of around 670 nm cause an increase in chloroplast production so it's important you have some energy at that wavelength. Except that's from memory and it could be 780. I can't find the reference now

And another fun fact: Blackman found that increasing light intensity above 2000 foot-candles did not lead to any further increase in the rate of photosynthesis.

[Harborseal]

So AscPete, you'll notice the green is the least efficient wavelength of light and your 4000K and 6500K LEDs from BML Horticulture have almost half their output in that least efficient part of the spectrum. I always take that into account.

So if all of the lights have the same lumens (not likely but hey... :- ) you'd have to multiply each wavelength % by the total lumens, multiply each of those by their relative efficiency - green 70%, reddish averages 95%, then add them up to get luminous efficiency for photosynthesis and compare those numbers, lol.

[AscPete]

Its simply that you need sufficient 'lumens' for a minimum of 1000 - 1200 FC ( lumens per sq ft) for healthier fig cutting growth when using a 'White' full spectrum light, where the 6500 K bulbs provide the best spectrum range for vegetative growth (more Blue), the actual math percentages have already been performed by the researchers.

[Harborseal]

Can you show me where any researchers have done the math for figs under those circumstances? Or even marijuana? Photosynthesis will always be more efficient with orange light than blue. That amount of light may keep your plants healthy, I have no argument there.

[AscPete]

I was referring to stem cuttings in general where there's lots of documented and anecdotal info from individuals, companies and institutions on the internet of the use of 6500K florescent (T12, T8 and T5) fixtures and recently more info on the 6500K LEDs for propagating stem cuttings using various propagation methods (Aeroponics, Hydroponics, Intermittent Misting, etc.).

Since this is a fig forum I inserted the "fig"

[Blackfoot12]

If anyone is interested here is a link to an LED build. https://www.youtube.com/watch?v=sGVSs657ziI
I have watched dozens of these and for me this guy has the best instructional on it. Also, if you watch his other videos he is a wealth of information on LED lighting in general. Now just a warning...these guys are growing pot so if that bothers you don't watch cause you are going to see pot being grown. I actually built this light and am currently using it. I also built 2 much cheaper lights using cheap components to learn about it. If you do something similar be careful! Cheap components can be dangerous. In the one light I had voltage leakage from the light chip to the aluminum frame. Meaning the frame was energized. Now it was only energized to 40V and I had the sense to test the frame before sticking my hands all over it and grounding myself. And it is only 40V. But it's still not safe. Point being...always be cautious and get and use a good multimeter.

[BrooklynMatty]

Harborseal What do you think of this lighting option? It was on sale at costco for $25 and i got 3 for the garage, but was planning on replacing one of my T8 Fluorescent Fixtures with this LED and using that T8 in my grow setup. I'm asking as it would be much easier to use this, if you think it would work for short term. Its 3700lm and 4000k which i know i'snt perfect.

http://www.designingwithleds.com/review-costcos-feit-led-shop-light-with-integral-lamps/

[Harborseal]

It'll work but you're getting a little over half the light for a little under twice the price compared to a walmart T8 shop light and 2 home despot bulbs. And I don't know why you'd think the LED version is simpler but if it's worth it to you than go for it

The T8 will work much better for your plants than the LED will, so that part of your plan is good. You should try to estimate how many lumens you currently have in the garage to get an idea of whether 3700 Lm will be enough.

[BrooklynMatty]

It'll work but you're getting a little over half the light for a little under twice the price compared to a walmart T8 shop light and 2 home despot bulbs. And I don't know why you'd think the LED version is simpler but if it's worth it to you than go for it

The T8 will work much better for your plants than the LED will, so that part of your plan is good. You should try to estimate how many lumens you currently have in the garage to get an idea of whether 3700 Lm will be enough.

It's simpler because it weighs almost nothing and is not in a hard to get to spot in my garage already mounted to the ceiling. Its also sitting in my office already since my garage is a hot mess.

I will most likely take down the T8 and put the LED in the garage, i already have a few lights in there so the 3700lm should be fine as additional spot lighting for certain areas.

[AscPete]

Update 10-30-16.... WARNING....

Although the LED Flood Lamps can be used as plant lights the actual light intensity and coverage for a typical 2' x 4' growing area is less than ideal. The florescent fixtures still provided better area coverage due to their actual size and light footprint. Custom fabricated LED COB Lamps work due to being fabricated with multiple chips (for proper area coverage) and are "engineered" for their high efficiency and increased output when under-driven with lower amperage.

All the Outdoor Flood Lamps trialed were under powered (under driven) when tested with a Kill A Watt meter. The 50 Watt Lamps were usually less than 30 Watts and a 140 Watt Lamp was only 100 Watts. This means that these Lamps are providing a proportionally reduced (usually 40%) quantity of light when compared to their claimed Lumens and Watt ratings. The Flood Lights, including the 140 Watt Lamp, also did not have enough light intensity (FC / Lux) to be placed further than one (1) foot from the leaves, placed any closer you would have increased light but decreased area coverage, only 1 to 2 sq ft. It appears to be usual practice to under-drive these Chip LEDs to increase their lifespans by reducing the heat generated and as a result the light output by installing lower wattage power supplies / drives. The 50 Watt Lamp should be provided with a
2000 ma or 1300 mA Driver depending on the chip Volatge (24 VDC or 36 VDC respectively) and the 100 Watt Lamp should be provided with a 4100 mA or 2700 mA Driver depending on the Chip Voltage (24 VDC or 36 VDC respectively) to provide the claimed Nameplate Lumens and Watts.

The COB chips in all the Outdoor Flood Lamps produced less than 1000 FC or 10,763 Lux at 12 inches away and dead center of the Chips, as measured by a Lux meter. At most distances and 12 inch radius from dead center of the Chips, the measured intensity, FC / Lux was less than half (< 1/2) of that measured directly above the Chip (dead center), so for most that had a measured 1000 FC at dead center the measured intensity at the 12 inch radius was actually less than 500 FC. The Flood Lamps lived up to their names and provided a flood of light at very low intensity, just slightly more intensity than the Florescent Tube Lamps which only had 1000 FC or higher less than 3" from the bulbs.

In a recent Topic, https://www.ourfigs.com/forum/figs-h...ed-bulbs/page2 don_sanders mentioned the $1.00 each Great Value 9 watt 800 Lumens A19 LEDs. I tested the bulbs at 6 inches apart (on center) with the light diffusion globes removed and they have outperformed the Flood Lamps, LED COB Chips and Florescent Tubes when it comes to Light Intensity as measured in FC and Lux at distances over 12 inches from the bulbs. With a spacing of 6 inches apart 20 bulbs can provide uniformly intense light over the 2' x 4' coverage area approximately the Lumens output of a T5 HO fixture.



I will test these bulbs in actual use during this winter and post any updates.

[Harborseal]

Are you talking about a 2, 4 or 8 tube T5HO? Your 20 bulb LED system uses 180 W nominally. How that compares to your T5 system depends on how many bulbs and the watts each. 54?

[AscPete]

4-bulb, 4ft, T5 HO, 220 Watts 20,000 Lumens.

[AscPete]

Just assembled the parts for a simple yet powerful DIY LED Grow Light, the actual "Build" and testing to come...


Its a "720 Equivalent Watts" / 104 watts actual / well over 10,000 actual Lumens / over 17,090 Lux (~ 227 PPFD) @ 18" from canopy, delivering light Intensity greater than one (1) 2 ft , 6 lamp T5HO florescent fixture and costing less than $40.00 no wiring skills required, its "plug n play". The four (4) outlets are connected in series, each is plugged into the end receptacle in the adjacent power strip. Only one power strip is plugged into the wall outlet and the lights (lamp) can all be turned on and off by the one (1) lighted on/off circuit breaker switch.

The material list and cost for the prototype with twelve (12) A19 LED bulbs;

12 - A19 9 Watt LED Great value (W-mart) - $12.00
12 - Polarized Sockets Adapters (W-mart) - $16.00
2 - 2 pk Extension Cords (L-wes) - $4.00
1 - pk #6 pan head screws (W-mart) - $1.00
1 - Silicone Caulk or Glue -$2.00
------------------------------------------------------------------
Total - $35.00

The LED Bulbs, Polarized Socket Adapters and 6 outlet power strips w/ circuit breakers are all UL listed and could all be purchased at W-mart. The only piece missing is a base to mount the four (4) power strips, the base could be a piece of 2 x 4 lumber, but I would prefer metal. The #6 screws are to mount the power strips to a base and the Silicone Caulk or Silicone glue is to permanently mount the Socket adapters to the Power strip. The available A19 bulb choices are Soft White or Daylight (2700K or 5000K) which can be used in several different ratios to provide light from seedlings to flowering / growing plants (all 5000K - 1/1 ratio - all 2700K).

[don_sanders]

Do you have a link to the power strips that you bought? I can't find any that cheap.

[AscPete]

@don_sanders
Those green power strips were from "Christmas" clearance at Lowes. The attached photos of white power strips are of the regular prices from W-mart.

[don_sanders]

Thanks. I'll have to see if I can find any.

[Altadena Mara]

I'm getting a lot of use out of Sun System light set up from the hydroponics store. The first year I had it on a trolley rail system that moved it back and forth over a plastic green house tent. The last few years I've had it suspended in the dining room. It covers a 4'x 4' area with ease and I've grown all my cuttings and tropical plants under it for the winter. It's nice just to sit there and be warm and sunny on cold gray days. So far this year the weather has been warm enough not to use it, but that could change.

https://hydrobuilder.com/sun-system-250-400w-digital-grow-system.html?utm_source=google&utm_medium=shopping&utm_campaign=900514&gclid=CKDm9-iovdECFQIaaQodiHED_w

[Atlatl]

Great thread ! Lots of good info on grow lighting. Thank you all that contribute

[AscPete]

Stumbled on this LED Marketing website this weekend, they are selling small modular grow lights. The site has some interesting info on small scale indoor gardening, seed starting and the Kratky Hydroponics.
.

.

The Happy Leaf LED light Version #1 is a modular Low Voltage magnetic power supply with removable 9 watt (60 Watt Equivalent) LED "Pucks". It is available with 9 Watt Blue /Red LED Grow Light Pucks. It has standard White LED Pucks, the 60 watt equivalents that are not available on the website...
https://fliproducts.com/agilux-usa/
http://www.happyleafled.com/shop/light-v1


.
The Version #2 is a dedicated "Full Spectrum" Grow light with Blue / Red / White LEDs.
http://www.happyleafled.com/shop/light-v2


.

.

It could work as a seed starting light or as multiple modules,
https://fliproducts.com/happy-leaf/
https://vimeo.com/175259122
The PAR Umol/m2/s numbers are somewhat deceptive (single point directly under light fixture) as is the claimed equivalency of a 150 watt HID, but its a novel idea.
.

[Vulsion]

If you are not growing commercial, you can make one yourself or just buy an LED grow light their pretty cheap these days.

[AscPete]

These 13 Watt A19 Household LED bulbs can provide equivalent PAR light / umols (each) and cost less for a 4 pack...

https://www.homedepot.com/p/EcoSmart-100W-Equivalent-Soft-White-A19-Basic-Non-Dimmable-LED-Light-Bulb-4-Pack-B6A19100WUL01/302539977

[pverdes3]

I've been using 2 of the E27 "full spectrum" bulbs with smaller output - linked below - in some old IKEA fixtures for 2 seasons now for my rooted cuttings. The full spectrum attribute means that they have an IR and a UV LED besides the blue and reds, and this helps in spring when transitioning to sunlight. The leaves were already used to UV and didn't burn so I think it worked. However if I would have to buy I would get stronger ones, as the 10W is barely enough to keep them alive. At some point in December they completely stopped growing, then started again when I moved them out and repotted.
Here is the current setup:

[SCfigFanatic2]

I use home made led lights each year.
This was last year with only a single 100 watt warm white led.

<a data-flickr-embed="true" href="https://www.flickr.com/photos/[email protected]/albums/72157674510787702" title="indoor plants under led since 10-10-16"><img src="https://farm6.staticflickr.com/5466/30061855154_9ae376c418_z.jpg" width="640" height="360" alt="indoor plants under led since 10-10-16"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>


Doug

[SCfigFanatic2]

edit picture

https://www.flickr.com/photos/[email protected]/albums/72157674510787702

thanks

[SCfigFanatic2]

That was lighting from one 100 watt 27 dollar kit I assembled
showing f4f how easy it is to assemble a led.

Or the more challenged can rig up a 10 led light bulb contraption
that will put out a few lumen. lol

Doug

[IrishFigMadness]

Just got my hands on a Migro 100watt LED. I'll be doing a thread on it once I get the grow room up and running. You guy's should check them out, i'd be interested to hear some opinions!

[CT ROB]

Where would I look for one

[AscPete]

CT ROB ,

https://www.migrolight.com/products-2/migro-100/

IrishFigMadness ,
Looking forward to your topic / thread...

I've been looking at the info on their blog for several months and and also linked to their website in several posts, but it was research for the DIY household LED's ... 12 - 1600 Lumens E26 Base (100W equivalent) LED Bulbs, 180 watts total actually provide more PAR photons and umol that the migro-100, but requires some minor skills to assemble.

[IrishFigMadness]

I'd never considered building my own light although i am aware of how much lighting companies inflate their prices. I was fortunate enough to get a deal on the light and the guy who builds them (shane) is literally 20 minutes away from where I live so if I had any issues I could easily get in touch with him.