Grow Lights


#21

It’s a heck of a lot cheaper than heating a greenhouse. That’s one of the greatest benefits. The downside is in a greenhouse you can spray the walls and floor and create humidity as well as make as big of a mess as you want.

But for 5-bucks a month for me to root these cuttings vs. not using my greenhouse is a real racket.

After attempting to use watering cans which either pour too much or too little with flats of seedlings or even those large tubs I currently have in use, I got to thinking why not buy a spray tank… the flow is perfect for watering. A simple adjustment here and there for whatever you’re watering puts you back in control.

Dax


#22

If u want good led grow lights u either pay for it or build them yourself. Check our tasty led, cobshop.net, timber grow lights, horticultural lighting group, and for diy, cobkits.com. cheap Chinese lights aren’t any better than hps and just being led doesn’t make them super efficient. Quality components make quality lights. Think meanwell drivers and citizen, Cree, and vero cobs or Samsung 3rd gen strips(https://www.digikey.com/products/en?FV=ffecdcb2)… 3000 to 4000k and 20w+ per sq foot.


#23

i was thinking of making a 5’ by 5’ by 7’ tent in my spare room framed with 2’’ by 2’ lumber’ and covered by uv resistant silver tarps. even the floor would be a tarp so it would be self contained, complete with a velcro door. frame a duct fan and have a vent hole to exchange air in there and control humidity. i know they make sealed grow tents but this would cost a fraction of what a grow tent would cost. i may have a winter project. :wink:


#24

I’m interested in your DIY led fixtures, could you tell me which led brand(s) you’ve used and where you bought them. And what kind of fixture/frame are you using? I’m using two 4 bulb 4 ft T5HO for vegetables and papaya plants, and they provide a little heat which is useful in the winter. But I’d like to add more and the electric bill is a concern. Do your led’s contribute any heat at all?

In the 3rd photo you posted, looks like a cucumber plant, some of the mottled leaves make me think of a spider mite infestation. Have you checked for that?

John

oops, I just saw your link for the led supplier, and the CobKits. What kind of frame did you mount the led’s in?


#25

Thanks for the heads up, I really hadnt been paying a lot of attention to that plant but you are right, spider mites. I hit them with some 8 insectide tonight and will do it again in a couple days. Explains why it hasnt been growing well. Ive used Cree, citizen and cxm22s from cobkits. Havent used cree in a year or two tho cuz the price isnt worth it.


#26

The random doo-dads to put your system together are surprisingly expensive. The led lights aren’t too bad if you shop around.


#27

If u have access to a metal recycling place that will sell scrap aluminium that can save a few bucks, u can use just about any piece with a flat surface as a heatsink.


#28


My grow lights. A lumigrow hanging over my six grow Towers. Also my LED strips which are part of my grow rack which is a full system. Both grow lights are red and blue Spectrum LEDs I am still learning a lot about this.


#29

to address your other questions, I source parts from cobkits, CDI, mouser and others. LED’s contribute just as much heat as any other light per w in an enclosed area. With any light nearly 100% of the watts used end up being heat eventually but where LEDs shine is that they convert a much larger percentage of the energy used into USABLE light before it is converted back into heat, when it strikes objects, etc. This allows you to use less watts to drive an equal amount of photosynthesis in the plants. Essentially with good LEDs you can use 400w to do about the same amount of ‘work’ that it took 600w of HID or florescent lights to do. This cuts down on costs and temperatures in your growing area. Depending on your climate this can be good or bad, in cool climates sometimes people have to actually heat their growing area when using led to keep the plants happy.

Another area where LED shines is in what they call ‘lumen maintenance’, all bulbs loose efficiency as they age but some do it much faster than others. Traditional HID bulbs and florescent should be replaced annually if they are used a lot because they degrade rather quickly. LEDs on the other hand last much longer, some studies suggest that they will only loose 5% of lumen output every 10 years or so, meaning essentially there is no reason to ever replace bulbs, reducing waste, hassle and $$$ for the consumer. Most cobs are rated at 50,000 hours, but people traditionally drive them softly in non commercial applications, which should greatly extended this, estimated beyond 100,000 hours, which is 11.4 years if ran constantly.


#30

COB lights can be super easy to build.

  1. COB Chip: AliExpress $3.43 - 50W Full Spectrum COB 110v. Doesn’t need a driver.
  2. Heatsink: Amazon.com - $16.99
  3. 12V Power Supply for fan: Amazon $7.89. Can power multiple 12v fans.
  4. Heat Sink Compound: Amazon $7.70 - A lifetime supply of high quality thermal compound.

You could also use a warm white COB for approximately the same price.

Edit: Spectrum does matter. I have a Theobroma Cacao in my classroom. One side is lit with a Philips GreenPower 32w White & Deep Red module. The other side has a Philips GreenPower 32w Blue & Deep Red module. The side getting blue has been putting out beautiful new leaves. The other side has no new growth.


#31

easy for you but my luck id burn the house down! don’t trust myself with anything electric.


#32

Thanks TheDerek and smatthew for all the detail. I hadn’t realized that heat (heat sinks, fans) was such an issue with LED grow lights. I could put that to use since my grow room is cold in the winter. Right now I have a heat mat under the plants/seedlings and I hung a plastic curtain all around the perimeter of one of the 4ft 4 bulb T5 fixtures…it’s like a mini greenhouse and the air inside has been in the 70’s so far. I wonder what kind of heat sink configuration would produce the best heat distribution downward.

TheDerek, about your spider mites. I don’t know if you have a strong enough (10x-20) magnifying microscope to see what’s going on, but with that kind of mottling of the leaves, I’d expect to find a serious infestation. There will be many many eggs all over the underside and lots of generations of those creatures, from adults to the near transparent young uns. It takes lots of attention to get rid of this kind of infestation. I don’t know much about insecticides since I don’t use them, but to do this properly you have to turn over each leaf(or cluster) one at a time and spray the underside and the stems (and trunks) while holding them… so your hand will get wet in the process. I’d much prefer to have my hand wet from fatty acids (Safer Soap) than some insecticide. Those eggs will keep hatching for a while so you have to keep spraying until you don’t see any more spider mites waving their many arms at you.


#33

I’ve been looking at this for a while and was about to pull the trigger on this one. It’s similar to the one Stan got, but with more watts (1000 vs 300). The plan would be to hang it at a reasonable height above my plants (figs, mango, jujube seedling, lychee, etc) in the living room, in front of the sliding doors to give the barely adequate sunlight a bit of a boost. Then, in the spring, I’d probably use it for seed starting as well.

Any thoughts about its suitability for this purpose?


#34

I’m just learning about this stuff, but that looks like a great deal. It has a larger coverage area than many of the more expensive ones too.


#35

Actual Power Consumption: about 185W

You get what you pay for honestly, chinese blurple lights are junk. I fell for a few of them at first also, before I spent some time educating myself. Actually if you want a decent light I have a couple chinese ones that I pulled the diodes out of and replaced them with cobs that would blow that away and Im not even using them right now… PM me if your interested

If these plants are in a living area, I wouldnt do blurple because its hard on your eyes also, warm white is much better.


#36

I often don’t see any mention of output in lumens. If I want to compare the brightness, equivalent watts doesn’t mean much to me. If someone says “1000 watts” it means equivalent and they could just as easily say 800 or 1400. I am not aware of any standard that properly defines what the “equivalent” number means. If that is true, than it is more a marketing term than a scientific term.


#37

last spring, i actually bought 2, 4 way splitters and put 4 14w 5000k led bulbs on each. popped off the plastic domes so you get full light intensity. works pretty good to cover a 3’ by 4’ area. use these for my seedlings with a heat mat and they grow lush. i keep them about 18in. away and they grow better than fluorescents 2in away. never tried them for bigger plants. should be able to daisy chain 4 sockets and use 4 of these splitters on a section of sheet metal to make a fixture? that would use 224w. could even go with stronger leds bulbs. i think a socket can handle up to 200w. these leds are very bright when you take the domes off. not sure of par output though. any ideas?


#38

with led its par thats measures the effectiveness not lumens. lumens is for people, par is what amount of that light is usable for plants. got that off advanced platinum led website. I’ve read it elsewhere too. i need to invest in a par meter.


#39

This works but you wont get as much light/$ as you would with cobs/strips/quantum boards. Good enough for seedlings and low light plants tho…

Danzeb, any blurple light will have very low lumens because, as the saying goes, “lumens are for humans” and are strongly weighted to green and yellow areas of the visible spectrum, areas plants dont need as much.


#40

OK, thanks for that info. Here’s a definition:
“PAR (Photosynthetically Active Radiation) is a region of the electromagnetic spectrum (400 to 700 nm) that promotes photosynthesis. PPF (Photosynthetic Photon Flux) is a critical metric that tells us how much PAR a light-source emits. PPF does not measure PAR at a specific location (e.g. your crop canopy), but it tells you how many photons within the PAR region are coming out of the light-source every second.”

How many sellers supply that information?