My Idea for grow lights...

[murihikukid]

I am having problems with what I thought was a simple question on other forums so I will put my idea here and see if there is a reaction because I am not a lighting or gardening expert
..I am trying to light my 4 X 5M greenhouse containing 60 Tomato plants (will be less next season) ...Now as I understand it based on comments received ,some people want me to buy all sorts of lights at a huge cost EG a grow light @ $30 per plant is $1800 and I would not even know what I was buying or if the product works.....plus there is the cost of being able to raise and lower these.....

I have thought that car headlights are a cheap option and I can get them for a tomato?? LED bulbs are getting cheaper ,and can be bought in a wide range of colour temperatures on Ebay...the headlights provides a reflector plus I can get the fusebox,harness,switches etc from a car to run as many circuits as I like via a 240 to 12V Power supply....I have been assured by a friend in Canada (who has all the brains here ) and he has thought this through and has designed a circuit for what he considers will do the job...Unfortunately its difficult getting hold of him at the moment...The lights are for light not heat ..thats what the i consider my plants require ...Now I may put TWO circuits or systems in because with my limited knowledge it depends on various factors ...It seems to me that by using headlights I could light up my greenhouse like the sun and using a combination of bulbs the light temperature would be between 2500K and 7oooK...My research tells me this is great for producing plant growth ..leaves flowers etc but what about the fruit ...when they arrive ...They have to ripen and I know cause thats whats happening to my crop this season (Downunder??)..Due to bad weather conditions I cannot get my fruit ripe ....

The reason (as I understand) is that there should be RED light (under 2500K ) at a ratio of at least 3 to 1 or even more and this is seen in LED grow Lights where one can see the diode colours and there can be up to 7 times more RED Led's than Blue LED's ...
So where do I get Red Light from..... Well I have various options ..

My latest madness is could I modify some headlight bulbs ...so far I have not got any answer from light foruns etc?? EG Could I exchange the diodes on a car 24 X LED headlamp bulb over to RED diodes ..after all I have seen some bulbs where the diodes look like they are just soldered on.. I wonder if possible and what is the degree of difficulty...Alternatively I have found other grow bulbs and I presume these could be used in a second circuit ..This could be a real asset ...and I think worth considering ..I could use circuit one till fruit appears and switch the second circuit on and run them together...But hopefully I can get some feedback on this....One thing I do know is growing seedlings etc inside under lights my Tomatoes really respond .Its quite incredible what a few CFL bulbs or Floro Tubes will do..and I want to get the positives out in my greenhouse for next season ..

So at the moment I am trying to discover if I am an old crazy man or a genius..When I find out if the above is even slightly possible i will rethink everything...........Regards Ron

[Worth1]

Fruit doesn't need light to get ripe.
Not only are you going to have to drop the voltage your are going to have to switch it to DC.
This is going to consume a ton of energy to run car headlights even if they are LED.
It will take a good sized rectifier to handle all of that currant if they aren't LED.
It wont take long adding up a bunch of car head lamps and you will be drawing as many amps as a welding machine.
This will require a good sized transformer/power supply to handle it.
Some time ago I got the wild idea to run DC to my garden and light it up did the calculations and dropped the idea due to energy consumption.
Not only is there a huge power consumption there is a huge power drop in the wires forcing you to go to bigger wire.
If I were you I would start thinking about CFL Lights in the 6500K range.
These are the lights that best mimic the suns output at noon day.
They are a full spectrum light.

In the US we use 120 VAC where you live I think you use 240.
The difference is you guy can use smaller wire because the currant is shared buy two hot wires not one.

Don't over think the light spectrum too much as most of the information is put out by light manufacturers selling lights.
They do this to get people to buy expensive (Grow) lights they dont need.
This information is then passed on by people and the misinformation continues to grow.

If it is just for fruit ripening like I said you need temperatures to increase not light.
In your case about 21 degrees C or 70 degrees F for me.

Worth

[drew51]

My first thought is car lights would be no where near powerful enough for tomato plants.
You need lights you can grow pot under as tomatoes demand just as much light. What is the lumen output? I just use T5's and get over 28 thousand lumens. From VHO lights. I would see this a a minimum so however many it takes to at least get that much light is what you need.
I just want mine for seedlings thus do not need any red light, all my lamps are 6500K.
Not all headlamps are equal! The 9006 for example gives 1000lm. A D2S Xenon metal halide arc has about 3000lm. So about 9 of the latter focused on one spot would work.

I use a T5 VHO and a T5 HO. The VHO gives out over 28,000 lumens with 4 bulbs.

The T5 HO is probably not strong enough at 20,000. Great for seedlings, but 8 foot plants? No! You need hemp grade lamps.

[Cole_Robbie]

Yeah, don't re-invent the wheel when it comes to lighting. Look at Metal Halide and High Pressure Sodium lights. Those are the two most cost-effective kinds. LED works, but I'd buy a real grow light, and not a cheap one, either. There are a lot of low quality LED grow lights on the market.

[Worth1]

Here is the rundown on why you dont want to do this car light thing.

Lets take 1000 watts for an example.
If you put a 1000 watt draw at 12 volts DC you will be pulling about 83 amps.
If you take that same amount of wattage on a 120 VAC circuit you will be pulling about 8.3 amps.

At 83 amps 120 volt AC for 100 feet total circuit length you would need 4 gauge wire at DC 12 it is off the charts you would spend a fortune on wire just to keep from burning the place down.

[ContainerTed]

Of course, you can put light bulbs in series and the voltage becomes less problematic. At 240 AC, 20 headlights would satisfy the voltage. The cycles, 60 here and 50 there is not a factor to the headlights either. Magnesium filaments in the lights don't care about AC vs DC. They only want enough current to fully excite the filament, thus producing the light. And that brings us back to the current (the amps). The electrical formula is "Voltage is equal to the Current times the Resistance". Thus, the resistance of the filament has a direct effect on the current for any given voltage. The higher the resistance, the lower the current.

My conclusion would be, "Without knowing the resistance of the filaments of the light bulbs, it would be impossible to calculate the Amps precisely, thus creating a safety issue like Worth was describing.

This safety thing is why I use "Florescent" bulbs for all my plants - Probably the easiest to do safely. Everything else produces a lot of heat that might not be wanted. I've built a lot of power supplies for this or that. I currently have a 12 volt supply that has a working capability of a bit more than 20 amps continuously. But even a few of those would not run a bunch of headlights.

I recommend you reconsider CFL's as being the only safe thing to do.

[clkingtx]

Worth, wasn't it you recently that made a fantastic light with cfl's and a shipping pallet? Maybe something like that(or several like that) would be most economical to light a 12x15 foot greenhouse.

Carrie

[Worth1]

Originally Posted by clkingtx

Worth, wasn't it you recently that made a fantastic light with cfl's and a shipping pallet? Maybe something like that(or several like that) would be most economical to light a 12x15 foot greenhouse.

Carrie

It wasn't a shipping pallet it was my old frame from my old T 12 florescent lights.

My wattage draw was 276 watts but the CFL lights were producing the equivalent of 1200 watts.
I was only pulling about 2.3 amps.

With the configuration I could have tippled it easy.
I know some folks here had a hard time grasping what I did and how it works.
Not only did I get fantastic non elongated growth but I also had tons of blooms forming and fruit set right here in the house.
Some of my first tomatoes of the season are due to this.
Done with 12 100 watt equivalent 6500K lights that only drew 23 watts each.
My thoughts behind it were energy savings and why put one 1000 watt light in and have the plant farther away suffer when you can spread it out with less energy consumption.
This allowed me to take the carbon footprint that I made smaller and transfer it to my motorcycle by going from 120 jets to 140 and burning more fuel there.
Here is one way to look at current/amps, watts and voltage.
For one thing watts were borrowed from the steam engine as a way of expressing energy.
Only later on did they start using it as a way to measure electricity used.

Volts are like pressure.
And Amperage is like current.
Lets put this in wiring.
I hate doing it this way but it works.
If you are using 12 volts you have less pressure like you would in pipe at say 12 PSI.
To get the same amount of energy from point A to point B you need to do one or two things.
Increase the size of the pipe or wire or increase the pressure or voltage.
Now lets look at resistance.
That would be like friction loss in pipe.
The longer the run of wire the more resistance you are going to have, the same would be for pipe, in pipe it is known as friction loss.
In wiring it is known as voltage drop.
With both your are wasting energy.
In pipe it is pressure drop due to friction loss in wire it is energy in the form of heat.
So what do you do?
You increase the size of the pipe or increase the size of the wire at a given voltage or pressure.
To put this in perspective if our electric lines were 12 volt DC they would have to be as big as huge tree trunks in our neighborhood to carry the amount of electricity we use.
A the time Edison had no concept of the amount of electricity we use today.
Thank God for Tesla and his 3 phase concept and AC current.
Worth

[ContainerTed]

From one who has both used, worked in, and taught Electronics and Electricity for 5 decades, I'd say that Worth has a good working knowledge. But Electricity is not easy to explain at any level. I DO believe that we are all trying to advise Ron that Automobile lights are not the best, nor the safest way to go. I hope we have communicated that to him.

Ron, even if you get the auto lights and manage to find enough of a power supply to run them, the cost of running those high amperage lights might be more than you'd have to pay for some CFL fixtures and lamps. You might even find a demolition site where there are CFL fixtures that range from "free" if you remove them to a couple bucks each.

I think the concensus here is that the 12 volt choice is not the safest route to take.

[Worth1]

Originally Posted by ContainerTed

From one who has both used, worked in, and taught Electronics and Electricity for 5 decades, I'd say that Worth has a good working knowledge. But Electricity is not easy to explain at any level. I DO believe that we are all trying to advise Ron that Automobile lights are not the best, nor the safest way to go. I hope we have communicated that to him.

Ron, even if you get the auto lights and manage to find enough of a power supply to run them, the cost of running those high amperage lights might be more than you'd have to pay for some CFL fixtures and lamps. You might even find a demolition site where there are CFL fixtures that range from "free" if you remove them to a couple bucks each.

I think the concensus here is that the 12 volt choice is not the safest route to take.

Ted do you mean florescent fixture ballast or CFL.
CFL is the designation for compact florescent light bulb.
Any standard screw in in light fixture will take them and my ceramic ones were very inexpensive.

This whole car light thing in the house came up years ago with someone and I.
I hope Ron got the information hes needs probably more than he needs.

Ted I have been experimenting and blowing fuses since the mid 60's.
Worked around power plants almost all of my life.
My neighbor is going to kill someone one of these days.
He buried 12 AWG THN directly in the ground no conduit about 4 inches deep 120 VAC in the flower beds.

Worth

[ContainerTed]

Ted do you mean florescent fixture ballast or CFL.
CFL is the designation for compact florescent light bulb.
Any standard screw in in light fixture will take them and my ceramic ones were very inexpensive.
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Both/Either of them. I got the feeling from the first post that expense was a factor. You know, that it's a case of "Watts per Dollar".

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My neighbor is going to kill someone one of these days.
He buried 12 AWG THN directly in the ground no conduit about 4 inches deep 120 VAC in the flower beds.
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Worth, I think I'd try to get myself on his beneficiary list. I had a neighbor in New Hampshire who did the same thing to put lights in his flower beds. He lost two pets and almost his wife.

The conduit might not be enough of a difference if it isn't sealed at all ends.

Burying wire is more critical than most folks think. Here in this part of Tennessee, there's a little green grub worm that will eat the insulation off any wires it runs into. Ran into it back in the mid 80's and was rudely reminded last year with a repeat for my nephew.

Ron, if you're still reading with us, let us know if we've been any help.

[murihikukid]

Hi ..Great Response .Exactly what I need to bring me down to earth again .....I have tried to read and understand many articles on greenhouse lighting , it seemed that general opinion was LED was the way to go...Is a question of cost and availability as far as Metal Halide and High Pressure Sodium lights.

I did find two Power Supply Units on an HP server ...Rated at 47A each...I never considered that running 12V lights would use a lot more power than normal 240v CFL lights and that there would be a safety issue ...Due to the extraordinary freight cost North America is ruled out for me as a supplier so that leaves Asia via Ebay...

I do have 9 x 5 foot LED Floro tubes and wonder how these would go .....Rest assured I am reading all the responses and taking everything on board ...I actually grow my cuttings inside in an old freezer stripped of the motor etc inside my front room?? ..Its stainless lined so reflects the light.....I have Ceramic head bulbs under the trays and eight floro tubes overhead but they are T 8's ...I think T5's require another holder.....Thankyou Ron

[Cole_Robbie]

There are countless companies selling LED grow lights, but the number of diode manufacturers is very limited; there are only a handful. Very few light-makers will tell you who made their diode. It's a sign of a reputable company if they will disclose that information.

[Worth1]

Originally Posted by Cole_Robbie

There are countless companies selling LED grow lights, but the number of diode manufacturers is very limited; there are only a handful. Very few light-makers will tell you who made their diode. It's a sign of a reputable company if they will disclose that information.

Cole I think one of the better companies is right here in Austin.
I posted the link someplace and I have no idea where or who it was.
They are doing some serious big projects in high rise grow systems.
Here it is Illumitex.
https://www.google.com/url?sa=t&rct=...nWT7qr4COaghxQ


Worth

[Jonnyhat]

A great idea to maximize grow space with less light is using light movers or light track, basically you purchase a HPS or MH grow light fixture that mounts on this device, it is basically a moving track that the grow light housing is afixed to. The ballast still sits on the ground but you gain a lot more grow area while pulling a lot less electricity. you spend less on bulbs, less on electric but still have significantly more grow space.