Every time I see a gardening with tech post I get mildly irritated now that I have been actually gardening for 5 years. I'm of the opinion that we need less tech and more systems with integrated design to take the human labor out of gardening and orchards.
The sun is the perfect light source for photosynthesis and temperature. I only use LEDs as a last resort for seed starting. Also LEDs don't provide the heat which plants really, really desire so you will end up needing to supplement with heating pads, incandescent bulbs, or external heating.
I accidentally raised my electric bill $100 one month last year when I used a small space heater to warm seeds.
I'm currently trying the following experiments:
* winter sewing basil using milk jugs outside in the snow
* sewing onions indoors and germinating them on top of my houses boiler.
At least where I live in Sweden we ain't getting enough natural light during the winter half of the year to grow small herbs for cooking, I've tried and have them sitting in clear view from the middle of a huge window (largest one I've got) and they still die, so I started putting them under some lights about 18 hours per day and they started not only regaining health but also accelerating in growth.
Now this wasn't any special light I just kept my kitchen CCFL's on and still saw some results however I've seen the results one can get with greater light system (especially paired with smart and learning control algorithms) as I've previously worked as a engineer/product developer on a light science company named Heliospectra were we could see amazing results not only in our labs but also at customers facilities.
I know you know this, as you referenced the pads, but FYI for the interested: you can get electrically-heated seed mats that only burn 20-40 watts, and cover a standard size.
I use them for both seed starting, and as a gentle, no-hot-spot heat source in my 3D filament storage/desiccant container. Even leaving them on 24/7 will only add a dollar or two to your monthly electricity bill.
I'm always charmed by the fact that when this site gets posted to HN so many readers don't realize it's for growing weed. The sun doesn't work if you get arrested when the plants sprout.
I have not really documented any of my tests thoroughly.
Gardening is tricky because it takes a year or more to test / verify ideas. It takes multiple years to prove or disprove a hypothesis, so _most_ of my work is actually just attempting to reproduce other peoples theory.
Its hard to know what is important to document and the process is slow.
Lots of my tricks and ideas have been coming from the permaculture movement. I use permaculture has a perspective or lens when qualifying strategies of my food growing systems.
There is many resources online and people teaching gardening on youtube which I spend my fall and winter months absorbing and then utilizing.
For a quick calculation operation cost of a bucket with 20W consumption (One CFL lightbulb) consumes 14.6 kWh energy in a month with continous operation. This costs about 500 HUF (~1.8€) according to the electricity costs i could find quickly (32 HUF/kWh ~0.1€/kWh).
This price is comparable to the price of vegetables in the supermarket. This seems economic only for special crops with higher margins.
Why would you do the calculation with compact fluorescent bulbs, when the project is really predicated on the efficiency of LEDs? Especially the red/blue LEDs that favor the photosynthetic spectrum.
I'm not saying the conclusion is wrong - this is generally about growing cannabis - but indoor cultivation is surprisingly economical for a variety of scales.
But that is a good comparison for a baseline, correct?
The real issue is that statement about costs being on par with a store...
How much time and energy would I have to input to get a regular crop of [Food-Item] that outweighs the travel time and cost to go get some at a store supplied by a vast industrial scale operation?
I would like to build a diet that is happy eating the same things as often as possible but the ingredients can be changed in their ratios that I get enough of a variety....
I think I could eat boneless, skinless, chicken-thighs for like 50% of the time, full veggie options for 40% and steak as an ingredient for 10%... (I envy my vegan friends)
disrupting the food industry and the palettes of people is hard.
Because at least Red LEDs generally aren't more efficient than CFLs.
You can find tons of articles claiming some lm/w record being achieved in a lab of 110 lm/w, 200 lm/w and other ridiculous numbers, but the reality is most of consumer grade available LEDs will only be 10-30% more efficient than a CFL, and probably _less_ efficient than a t5 fluorescent tube.
I've looked into this extensively when running an indoor garden, and in the end decided to go with FL tubes and a 400W HPS (which was far better than any LED on the market in 2010)
who cares about initial costs when you're designing a sustainable system? If you spend $5k / yr on groceries, are you really going to be upset about spending $1k on lights 10 years later?
But to answer your question directly, the efficiency of LED vs CFL in terms of lumens per watt is about 2:1, so on that basis alone the payoff of running for 14 hours per day is about $8 / year / bulb. However, since the bulk of fluorescent output [0] is in the useless trough of photosynthesis sensitivity [1], it is closer to 4:1, so the payoff between your linked $5 bulb and a $35 PAR-tuned grow bulb would be a little under 2 years.
Anyways! Here's my calculation. 4 of my cfl's for $10, four of these: http://www.homedepot.com/p/Philips-100W-Equivalent-Daylight-... for $28. The cfls use 23 x 4 = 92W while the LEDs use 14 x 4 = 56W. That 36W difference at $0.12 per kWh will take 4166 hrs (~300 days at 14 hrs/day) to make up the initial cost difference. I googled up weed growth, looks like about 72 days so you can get four pot plants through this thing before you start to regret the CFLs.
You don't use daylight LEDs to grow plants though. The "Green" spectrum is completely wasted. I don't know about weed (I was growing algae in a photobioreactor for a time) but you need a single-wavelength red LED to get biomass growth and blue LEDs to make the thing 'flower'. By using only the wavelengths that photosynthesis requires, you save a substantial amount of energy per photon. It was more of a concern for enclosed PBRs but not having to dissipate all of that heat was a big boon for energy saving too.
So this is actually interesting but it seems that algae is different. I found this subreddit which seems to be the home of a huge spacebucket nerd. Anyways he's got citations but I'm also not experienced enough to really evaluate them. Here's the interesting parts:
>If you find a chart with a deep dip in the green area then it's for some sort of algae or bacteria, not green terrestrial plants. If you find a chart with a bunch of chlorophyll and other pigment peaks then it's only valid as an extract in vitro (in the test tube or cuvette) and not in vivo (the living leaf itself). The pigment peaks can differ depending on the solvent used and the charts do not tell how much there is of a particular pigment so take them with a grain of salt. They are only valid for the particular set up used.
As a warning the Wikipedia page on photosynthetically active radiation uses these incorrect charts.
Most biology text books get the above paragraphs wrong by not showing the McCree curve while also not articulating how our eyes perceive different colors/wavelengths of light. This is a well known problem with botanists who specialize in plant lighting and causes a lot of confusion and misconceptions. Even Botany for Dummies gets it wrong which is otherwise a very good book.
>Here is a spectral reflectivity profile of a high nitrogen marijuana leaf (Jack Herer). About 90% of the green light is being absorbed (it's on an 18% reflective gray card used in photography) although many plants may be closer to 80% absorption. Plants can use green light and at higher lighting levels green is more photosynthetically efficient than red (pdf file). All the latest research and my own experiments back this claim.
Thanks for the link, I'll check it out in more detail in the morning. I worked with an algae biofuels company so for fun we messed around with a lot of different light types with various strains. We got some crazy growth rates using a flat PBR with ~3:1 red:blue leds and no green whatsoever. Our best outdoor open pond results were about 25G/m2/day (on a 30cm deep, 1/2 hectare pond) but with the right leds we could do the equivalent of several hundred g/m2/day. We had good luck with high frequency pulsing too which further cut the energy usage.
Edit:
That user definitely seems to know their stuff, all the math and logic around quantum flux and measuring photon output seems solid. It seems that green light is more beneficial in the presence of white light which makes sense from what I remember of photosynthetic apparatus (I left that co. ~2 years agoso I'm definitely rusty). Id be curious to know why the green response curve is so different between algae and plants but perhaps an investigation for a different day.
Yeah, I like how the article shows tomatoes and peppers. You'd spent fifty bucks to grow, like, $1.50 worth of vegetables. I don't think you'd ever break even just on the power. Not to mention the veggies will probably taste better if you grow them in sunlight.
And you'll still get caught if you grow your weed in buckets unless you have a separate source of power.
In many regions of the world, the only way to grow fresh greens year round (lettuce, spinach, any Brassica oleracea species) is hydroponically. I do happen to like some nice crisp kohlrabi in the summertime, but it even becomes rare in grocery stores at that time of year. If the world climate continues to warm without check, this produce will become even rarer in stores.
The approach done by spacebuckets isn't very efficient. I haven't looked at the site recently and it currently seems to have been hugged to death, but LEDs have a dramatically lower energy consumption compared to individual CFLs, especially if you use one converter and run them all on the same DC circuit.
There are also parts of the world where you could run this concept economically using solar panels to provide greens that are normally impossible to grow out of season without the added cost of transportation. (You would also have to cool the building, of course, but that can also be done in a carbon neutral fashion.)
60 lm/W is very low these days. Commercially available screw-base A21 bulbs like Cree's "100W replacement daylight" (17,000 lumens at 15W) are up over 110 lm/W. You can get that for $14 at Home Depot.
It depends on the quality of the LED and what it's designed for. Some deliver better spectrum response for plants and for different parts of their life-cycle. Vegetative and flowering stages may require slightly different optimal amounts of energy at particular wavelengths but it's not strictly necessary. A good LED lamp designed for growing should be more than adequate, then tend to have fill-ins for the wavelengths needed.
however, at least during the winter months, any waste heat given off should technically offset one's heating bill. It may not heat your whole house but since "energy cannot be created or destroyed", it should help at least part of the year.
Only if you have resistive electric heat. Resistive heat is a simple X electricity -> X heat added to house. A heat pump uses electricity to move heat from one object to another, so it's X electricity -> Y heat pumped into the house from outside, where Y has some efficiency limits, but isn't directly bound by conservation of energy.
The effective heat gain here is more than 100% of the electricity spent, and we measure it with "Coefficient of Performance" instead of "efficiency". A good system is somewhere around CoP 3.5, making the LEDs a comparatively bad heater.
I don't think his point is that it's a great source of heat, just that electricity used on the LEDs is either being used as light by the plants, or as heat by the occupants of the house, so in a sense, the waste is minimal
All plants are welcome, the community does not judge species. For us plants are just plants, we want to become "a melting pot of photosynthesis enthusiasts", as per the bucket manifesto. There are many cannabis growers but that is because it is a very popular plant around the world (and very expensive too).
I've grown a lot of different plants in my buckets, including thyme, dill, basil, hot peppers, cherry tomatoes, strawberry and chives :)
I've been thinking about doing something like this, since I'd have to fence my yard to have an ordinary garden if I don't want deer to eat all my plants.
Are there any concerns about levels of non-growth-limiting (or color-affecting) nutrients in container-grown veggies? Has anyone even looked into that?
It is expensive because of its legal situation. Cannabis is essentially weed and is very easy to grow, thus if not for the law, it is actually very cheap.
Yeah, this site used to be 100% about growing cannabis. Not sure when it transitioned into showing tomatoes and peppers on the front page. Ask yourself why these buckets have lids and air filters? It's not to keep the sweet aroma of your tomato plants out of your apartment =)
But, does it matter? Still some really nice DIY designs here even if you aren't growing weed.
IIRC it started mainly as a cannabis community but it's "branching" out to include other veggies - the growing method works for any plant, it's down to the individual as to what they grow. Feel free to experiment with different plants from different climates!
Well, I hope this one doesn't. Something on my bucket list (no pun intended), is to do something like this on a scale of 10-20 units (buckets?), except maybe in cubes with better climate control with a rolling schedule for a variety of veggies - fresh veggies year round, yum.
Quick example - lettuce can go from planting to harvest in roughly 7-8 weeks. So 7-8 buckets could provide you with fresh lettuce every week.
Edit: Apparently it's possible to manipulate the light cycles to get lettuce to mature in just 22 days! That's only 3-4 buckets :)
I've done this with bell peppers and its a lot of fun. Ask your local deli or bakery for free food grade five gallon buckets. Mine smelled like frosting which was not necessarily a problem. You probably don't want to reuse a bucket that held paint thinner or weed killer in its previous life.
Peppers not being illegal, I didn't need all the indoor lighting or air filters or automation, I just grew them outside in the back yard where anyone could see them.
One year I tried drip irrigation mostly to discover I need to weed and harvest daily and automatic watering means I'd skip that to my detriment also rodents like the taste of drip irrigation tube, the effort to keep it running exceeded the effort saved over simply hand watering.
You can buy "container gardening dirt" that contains weird mysterious substances that hold water so you supposedly don't have to water as often, I found they grow a crop of mold and moss which lowers or eliminates production. Of course if you live in a desert maybe humidity isn't a problem.
It is not rocket surgery for even a noob wood-butcher to turn some 8 foot long cedar planks and some posts into attractive looking planters holding IIRC 7 buckets per planter with plenty of drainage. Cheaper wood is too expensive to use because it rots quickly. My cedar planters are like a decade old and still look new(ish).
The problem with indoor lighting is I ran the numbers on an "Aerogarden" product and it works financially for basil (and apparently weed) but not crops like lettuce. The problem then becomes what do I do with an infinite supply of normally expensive fresh basil? Its possible to get tired of pesto although initially it sounds impossible.
Even for things like basil, I don't want to break even, I want to feel like my work was worth something.
I live in a townhouse and have a very small garden, about a 3x9 foot patch. I grew about a 3x3 area of basil and was able to make enough pesto for about 15 meals thoughout the summer, since I usually pay about $3 per bundle of basil I felt I got about $45 out of my basil patch. Of that $45, I spent $3 on basil seeds, and probably another couple dollars on fertilizer. Of course, there is additional value in having fresh basil on demand.
By the way, basil can root from cuttings purchased at the grocery store. Its easier and more effective to just buy seeds, but some people have trouble with them. I put some store bought basil in water and it rooted just fine, then continued to grow into a nice plant.
How many plants could you fit in a bucket? Perhaps you put 3-4 different herbs in each bucket, so you have a good chance of using something in your cooking before having to replant the bucket.
There's no thin veil here, that's how these things started and why they're called space buckets. Indoor gardening w/ grow lights generally isn't economically viable for most readily available varieties of produce.
I know when I posted on there about my peas/tomatoes I had some people surprised that I was actually growing those plants and not using it as a euphemism. They helped me with my plants and setup nonetheless
i used to grow weed with old sodium and halide fixtures, and as i grew older i had a nice rig and filled it with cukes, tomatoes, peppers, strawberries, peas, string beans, herbs, lettuce. even at the time with the larger power cost i thought it was totally worth it to be able to go down into the basement and make myself a fresh salad or have ripe strawberries without leaving the house.
my only issue is that once you move off the easy plants (that dont mind alot of water), it basically stops working. it isn't worth it to try to deal with moving and keeping soil in good shape in a closet.
The only bad thing is the socially unacceptable shadow that it casts on high tech gardening.
High profit crops are needed to push the state of the art environmental control designs forward and costs down for other crops; which will become increasingly common as systems mature and costs decline below that of traditional production methods.
Since pot is legal to grow (either freely or with a medical license) in California, Colorado, Washington, Oregon, New Mexico, Nevada, Alaska, Arizona, Massachusetts, Michigan, Maine, Delaware, Georgia, Maryland, Montana, New Hampshire, Rhode Island, Vermont, Florida, D.C., and Hawaii, I'm not sure it's so "unacceptable" anymore.
I get really tired of the voluntary blind spot people adopt about this. Legalization is happening for medicinal reasons, and for economic/justice reasons. Not because people everywhere decided it's good for you recreationally. It's not this binary thing where all of a sudden it's the same as, like, knitting as a hobby. Growing it also doesn't inhabit the same moral space as growing wine grapes in your back yard, or even brewing beer in your garage.
> Growing it also doesn't inhabit the same moral space as growing wine grapes in your back yard, or even brewing beer in your garage.
Says you. I fail to see any reason see why wine making is morally better than growing cannabis, or why alcohol use would be morally better than cannabis use.
One might be more common, but it's certainly not more moral to do.
All I know, and what I think he's saying is that if I were to tell my friends and family that I grew that (which I don't) they would all redicule and/ore disown me.
And a lot of people I know would be in the same boat. Is everyone like that no of course not, but I'd venture to say a significant portion of people are(not necessarily majority, but a lot)
Maybe. The problem here is, unfortunately, in several incidents, merely shopping at a hydroponics shop has been enough for police to put you on a "suspicion of growing marijuana" list. (Example here: http://www.tampabay.com/news/publicsafety/pinellas-hydroponi...)
In the states that have legalized marijuana to some extent, this may be less of a problem these days. That still leaves a large amount of states where this may still be an issue, and potentially create hassles. Kansas is not on your list, for instance, and it was pretty easy to Google a similar incident there: http://www.kctv5.com/story/23951053/leawood-family-seeks-7-m...
This is unfortunate, because high tech gardening absolutely has applications beyond weed. Even if it's more niche / luxury (for instance, restaurants having indoor gardens to ensure a supply of super-fresh veggies and herbs) or hobbyist (like the African violet grower comment below... even largely idiot-proof versions like the Aerogardens exist for this market) due to the economics... these applications do exist.
Right, I should have said frowned upon as the legislative tides are slowly changing. Only 8 / 50 states are recreationally legal and even in these states employers still use drug testing as a pre employment filter indicating some level of social stigma still exists.
The rate of growth is something else to consider. From two states (Colorado and Washington) last year to at least three more this year (MA, ME and CA). And I didn't even notice that DC, NV and OR crept in as well.
Yes, some social stigma exists, but it's on its way out. But I agree with you as far as: It may never reach full U.S.-Wide legalization. And employers may never get over it.
Note though, that medical as > 50% adoption by state in the U.S.
Including CBD only medical states, > 85% have some form of medicinal; only Texas, Idaho, South Dakota, and Kansas have no form of legalization if you include hemp.
The profitability being high it promotes bad engineering "who cares how much it costs, who cares about the electric bill, you can buy a thousand heads of organic lettuce with profits after selling the weed". Then people try to grow lettuce directly instead of using weed as an intermediary and its not nearly as successful therefore the whole idea must suck or something. Although with better engineering, perhaps indoor lettuce growing could be technically and economically successful if the entire marketplace of weed wasn't stacked up against it.
Sort of a bad money pushes out good money scenario. If it weren't for profitable indoor weed farmers, you'd have higher technology level indoor successful lettuce farmers, and eating is more important to the world than getting high.
Its a scalability argument... when used restaurant fryer oil is free, turning it into free biodiesel is a win, until restaurants start selling used oil and making exclusive deals until its cheaper for everyone to burn diesel instead of making biodiesel, at which point the schemes collapse and used oil again becomes worthless trash. You can feed "A" hippie by selling indoor grown weed and buying produce at the store but you can't feed a planet by having everyone grow indoor weed and buy produce (from who?) at the store. Eventually everyone into weed is going to grow their own and the market will collapse until no one can grow indoor weed and the cycle might repeat.
>Sort of a bad money pushes out good money scenario. If it weren't for profitable indoor weed farmers, you'd have higher technology level indoor successful lettuce farmers, and eating is more important to the world than getting high.
I think you've got it completely backwards, if it weren't for the indoor weed farmers making the market, there would be little development in indoor farming at all.
Yep. My other half grows and hybridizes African violets in an indoor setup which, because we're in Scotland, includes some pretty bright grow-lights on a timer. We keep joking about him potentially getting raided due to his shopping list and browser history.
I remember reading at least one case in the US where a home grow operation was discovered by the amount of power it was using, too -- the electric company noticed.
I saw a picture of a raid the other day in the area I live, where they found a growop because it was the only house in the row whose roof didn't have 10cm of snow on it. Quite a funny sight.
As part of my law degree I spend some time in courtrooms, just watching cases being heard, many of them about small time growers. Many people caught growing at home are punished twice: first through criminal law, and then through civil claims like from energy companies and banks or landlords. Very often these people have no other option then to start growing again, pushing them into a vicious circle. (They made the initial choice themselves, not spinning a sob story here - just saying that the stories behind these cases are quite interesting from a human interest point of view).
> Many people caught growing at home are punished twice: first through criminal law, and then through civil claims like from energy companies and banks or landlords.
Why would the energy company sue you if you paid your electricity bill? Same for landlords or banks, if you paid your rent, who cares?
On phone yesterday so I couldn't put all those details in.
Essentially yes if you pay your energy bill, there's no problem, but almost always the electricity is taken illegally (by bypassing the meter, or otherwise tampering with it) because otherwise the energy provider will notice straight away that your usage is abnormally high (this is the relation to the GP that prompted me to write this). Also, for a proper growup you need (much) more power than a residential supply line provides. The energy supplier then starts a civil procedure to get their money back, sometimes going after the landlord if that landlord could/should have known something was up (some case law includes that neighbors complained about abnormal heat in the house; the landlord should have followed up and is therefore liable for damages, as well as criminally (!) liable for aiding and abetting.
Land lords: they will cancel rental agreements the moment they find out you're growing weed, whether you pay rent or not. Banks will cancel mortgage agreements when a plantation is found. Furthermore, mayors can close a house for (IIRC) 6 months; meaning nobody can live there, but if the land lord doesn't cancel your rental agreement, you're still liable for the rent. Plus you have to live somewhere, because generally you won't be in jail that long. And if you have a family or live in your parent's house - let's just say that there are some heartbreaking cases arising from this.
(also, I should have specified probably, this is in the Netherlands. People think that NL is an anything goes area when it comes to marijuana, but it's really not - if you're caught with a sizeable (i.e., not just for personal use) grow op, you're royally fucked, especially if you don't have much money to begin with - which is generally why people do it at all, because it's not like you'll be a millionaire from stuffing your attic or basement with a couple dozen/hundreds of plants).
thats the worst part. i've seen lots of sketchy meter bypasses. and while it hides you for a while and makes the electricity cost disappear, its often a massive hazard. not just tapping off the initial drop (if you kind of know what you are doing, it can be ... not so bad?), but some of the wiring jobs i've seen defy belief.
There are many cases of this - but typically the ones I've seen reported have been easily distinguishable from any reasonable personal usage. Entire (rental) houses given over to dense growing in every available space. Having a few (or a dozen or 30) pots/pods/whathaveyou in your own home wouldn't look anything like it.
Heck, I remember cases where they've used thermal imaging from helicopter to identify such buildings.
I believe it's pretty common practice; not just the amount of power being used as a red flag, but obvious patterns too - for cannabis you normally have it going for 16+ hrs of light for it's vegetative cycle, then switch to 12 hr of light for flowering, so they can use that pattern too.
Presumably this stuff is only checked post-suspicion, and not automated and parallel construction stuff done.
ha! this is exactly my fear. I really want to start an indoor rose collection, but I'm almost positive that the shopping cart i have on amazon is going to put me on a list... I think i'm going to find a local shop and take uber :)
I'm pleasantly surprised by that selection! I expected aerogarden clones, which are IMO way to productized and small for any kind of serious gardening, but those ikea racks are close to what you'd find in a real hydro setup for nursing seedlings/small plants.
I have my own space bucket and I use it to grow my own food, it's a powerful gardening tool if you don't have much sun hours at home, also you get control of all the process
you joke, but the marijuana industry has long been at the forefront of DIY hydroponics and cultivation in general, in much the same way that the porn industry is an early adopter of various web tech. being the underdog leads to some fruitful risk tolerance.
I think the greatest advantage of indoor gardening isn't the ideal lighting and temperatures so much as pest and humidity control. Indoor gardens don't suffer from birds, insects, and rodents like my outdoor plants. (Or my Mom's chickens =P) In addition they don't require half as much water as my drip irrigated plants.
Even if you just keep the plants in the garage it's a huge advantage if you live in an area with lots of pests. Also with the emergence of cheap LEDs you can keep light on the plants without the huge energy costs of fluorescent lighting.
Not to mention it's kinda pretty to have walls of plants in your house =)
One of the reasons I dislike living outside of the US is because sites like this only have amazon.com links. It would rule if you could swap them for your local amazon (amazon.de for me) links somehow.
The problem at least for me between .com and .ca, is that they seem to be fundamentally different sites with their own separate arrays of sellers and products that can be quite different from each other. There are many things sold on .com you simply cannot get from .ca, or even shipped to Canada from the .com site
Yeah, exactly. Each amazon site has 100% different products. You have to just search for the same product and hope it's there, or find something similar. Even more difficult when the other site is not in English.
Which is a bummer, because a lot of these sites are supported by affiliate links. When you go to your own amazon, you lose the affiliate connection and can't support the site that gave you the information.
Interesting, I've always been curious if it doesn't make sense to have a clear unit with some sort of cover and LEDs to "top up" the natural sunlight in northern locations during winter. Not sure if it just ends up being the angle makes the spectrum useless... but always seems like the completely enclosed environments are throwing away a lot of free energy.
One of the reasons why they choose to use Buckets instead of Tents is because it's very easy to transport the bucket from place A to place B. With the tent it's not as easy.
yes. maybe not initially but once they settle in they are there for good. treat with insecticidal soap once a week and rinse it off well (move your buckets or tubs into the shower)
It'd probably be related to the higher blue light levels of "white" LEDs. I'm sure the amount of screen time most people get these days has a greater effect than LEDs in a bucket.
The sun is the perfect light source for photosynthesis and temperature. I only use LEDs as a last resort for seed starting. Also LEDs don't provide the heat which plants really, really desire so you will end up needing to supplement with heating pads, incandescent bulbs, or external heating.
I accidentally raised my electric bill $100 one month last year when I used a small space heater to warm seeds.
I'm currently trying the following experiments: