Grow lights, heaters etc, on a budget

Evening all.

I'm thinking of setting myself a mission to grow 1000 plants from seed for next year. There is logic behind this whim. Firstly I want to make some swift progress on my garden on a budget, and secondly I'm thinking I might try to sell some plants to make some pocket money.

I'm thinking I might need some kit so that I can get off to an early start. I don't want to spend a fortune partly because I haven't got a fortune, but mostly because I'm always tight when trying something new. My philosophy is do it cheaply, if it works out, upgrade as required, if it doesn't, little loss.

So, any suggestions on kit I might need?

 

I saw this one:

http://www.ebay.co.uk/itm/225-LED-H...dsBulbs_JN&hash=item27c8644807#ht_4775wt_1271

Its basically an LED array, about 1ft square. I was thinking of mounting it inside a wooden cabinet, with a mesh shelf above it, for seed trays containing seeds that haven't germinated. Then the limited heat from the lamp might speed germination. Then the germinated seedlings go to the bottom shelf, under the light array, where they remain until about March, when they can go out to the greenhouse or a cold frame.

 

My prediction is that they won't give enough light to do any good.

If you want to know about lights then best place to read up is on the Cannabis forums, those boys have got it down to a fine art.

You need the lights as close as possible [i.e. without burning] to the plant, so low-heat bulbs help with that. Then you need as much light as possible.

The benefit of light, as I see it, is that you can grow plants in a structure that is much better insulated than a glass/plastic greenhouse - in your house, or in an insulated "room" in your garage. Downside is that you have to spend money on producing the light, but it is probably less than the cost of running a heater, and there isn't enough light to bring plants on in a heated greenhouse in late Winter anyway ...

The other problem is space. Seeds can be sown close together - even if you hand-space them in a seed tray they'll only be 1/2" or maybe 1" apart. But the moment they need pricking out you'll be moving up to 2" apart in modules, or 3" apart in pots - that's 4 to 9 times the area required. So you perhaps need to think about how many pricked out plants you can fit in your growing space.

Another approach is to bring them in at night. They'll be happy in the dark on the utility room floor, or similar. In fact they'll be happy in there for a few days if we get a really cold snap in March.

I have a cheap "blowaway" inside my unheated conservatory, and I put my grow lamp in there. That produces enough heat to keep it at 10C at night from March onwards, and the plants get an extra 7 hours of light each day.

 

Thanks Kristen. Much to think about there.

I have a utility room (former garage we think) attached to the house, which has a south east and a north west facing window. Temperature in there wont drop below about 10'C unless we get another arctic winter. Maybe if I scrap the cabinet idea, and go for some arrangement of daylight-through-window + chap grow light, maybe I can make it work.

 

Artificial light supplementing day light will help. You still need to go for the maximum amount of "light power" (Lumens) that you can.

 

I know the one I bought wont be anything beyond 'basic', but I'm thinking ball park figures, its 15W on LEDs. Given the efficiency of LEDs compared to other types, I would hazard a guess that that's roughly equivalent to about 120W on an incandescent lamp. The conventional ones I looked at tended to be around 600W, but again ball park estimates, about half of that is the wrong part of the spectrum (LEDs are very precise), and about half of it is heat. LEDs being cold light means I should be able to place the lamp literally millimetres away from the foliage without fear of burning anything. So, by those very loose estimates, I'm hoping that what I've ordered is at least as capable as a 600W 'conventional' hydroponics lamp.

 

My 600W Metal Halide bulb runs very hot, consequently it has to be 24" away from the plants, but that also means that it "covers" an area of about 2 sq.m. ... I think you would need a lot of LEDs to cover 2 sq.m. if they were only mm away from the plants?

I'm sure L.E.D. is the future for supplemental lighting, just not sure (price / performance) its just yet.

Downside with Metal Halide is that you need a "choke" (called something else, I've forgotten) which is chunky device for high wattage bulbs, so quite a lot of clobber.

Metal Halide is well suited to over wintering plants because it has to be 24" away from the plants it, in turn, has good canopy penetration and whilst that will also do well for seedlings they are just as happy, being of uniform height, with fluorescent tubes / L.E.D. - you just need a lot of bulbs, close together, to in the case of fluorescents [cost of] lots of fixings & starters, and L.E.D.s lots of bulbs.

 

Clueless - I think you have two problems - growlights and space.

Growlights
When I built my lightbox I did a fair amount of research. There are really only two types of light that you would consider. Fluorescent tubes and metal halide. Long life bulbs are small coiled fluorescent tubes but they are not as efficient as proper tubes. Incandescent bulbs are far too inefficient; and to date LEDs, which are efficient to run, are too expensive to buy. Consequently, although your LED panel appears to be cheap, I suspect that the light output would be low.

There are two important measures of light - lumens and lux. Lumens are a measure of the total amount of light emitted by a light source, and lumens per watt is the measure of the efficiency of a light source. Lumens per watt is essentially the total amount of light you get per unit of running cost. Fluorescent tubes and metal halide are roughly equal in lumens per watt, and nowadays LEDs can be the same or even better - but still too expensive to buy.

However what a plant needs is lux, and this is the amount of light that is received per unit area, ie how much light is received by the leaves. In terms of lux, fluorescent tubes are more efficient than metal halide. The reason is that you can put plants very close to a tube, which is relatively cool. But metal halides run very hot and so must be further away from the plant, and the farther away you get from the light the less light is received.

All lights produce about the same amount of heat for the same wattage as nearly all the electricity is turned into heat and only a small portion (perhaps 15%) is turned into light. You can have a single metal halide bulb of 600 watts which would be very hot, but you would need 60 feet of fluorescent tube to get the same wattage and amount of light. Being so spread out is what makes the tubes cool to the touch.

As a result, fluorescent tubes are very good for seedlings and cuttings as you can put these very close to the light source and as you are makeing more use of the light you will have a lower running cost. But if you want to grow large plants you need to have a very powerful light source to get sufficient light to the base of the plant, and this can generally only be achieved with a metal halide bulb. But the bulb will be hot so it needs to be a distance away from the plant and so a greater percentage of the light will be lost.

In my light box, which I use for seedlings and cuttings, I have three 3 foot long fluorescent tubes (90 watts in all) over a growbag tray and find that this gives about 10,000 lux at plant height, which is almost the equivalent of a summer day. Actually daylight levels can be much higher, but you also get cloudy days and less light at dawn and dusk in daylight compared to a light box.

Space
It would not be too difficult to raise 1,000 seedlings under lights, but as Kristen said your problem comes when you pot them up and they take up 100 times the space.

 

Thanks Peter. Lots of useful info there.

I'd be interested to know more about your light box. It sounds like the kind of thing I was thinking of building.

 

Here's the cheapest power option I can find for you Clueless.
It should remove your limitation issues:-
http://passionford.com/forum/genera...yone-tapped-into-a-streetlight-for-power.html

...but keep your head down

 

Excellent post PeterS

Only additional point I would make is that heat from Metal Halide can be useful. I have mine in my blowaway "tent", inside my unheated conservatory, in the early Spring, timer set to night-time, and it provides all the supplemental heat thus avoiding also using a heater. Moot point for a grow-box inside the house though

 

There was a thread on this subject earlier this year which had a link to a 2010 thread in the first post

http://gardenerscorner.co.uk/forum/threads/grow-light-germination.39483/

 

Hi there.

Does anyone know if these are any good?
http://www.amazon.co.uk/Dual-300w-H...YBJ8/ref=sr_1_1?ie=UTF8&qid=1349865326&sr=8-1

 

Standard grow room CFLs.

Dunno I'm afraid. They cast light in all directions, thus half of those tubes (1/4 of the light) have to shine "through" the other "tubes" to get to the plant. Half (the light) shines up, to a reflector, but that's the same as any other bulb.

I wonder if [long] fluorescent tubes don't shine more light directly downwards?

Plenty of the Hardy Tropicals bunch use them just dangling over/near the plants to keep them on tick-over (e.g. in a frost free garage). That avoids the cost of a reflector, and a fitting + starter for a tube. But I personally don't think that would be enough for "growing" rather than "tick over" -unless you also had a reflector and, at that point, maybe?? tubes are better/same price??

What are you planning to light? Over winter tick-over / growing on plants through winter / seedlings?

 

Hiya Kristen, thanks for the reply.

The plan is to make a light box of sorts. I was thinking maybe two of these (along with reflectors) would be enough to light up my 1m long propagator? I would want to make it light enough to make Tomato growing less problematic, oh, and there's the Onion Challenge Two of these, according to the spec, SHOULD give out 600w. Surely, that's enough?

Cheers...Freddy