Are LED grow lights worth the money, and which should I buy?

[BertieFox]

LED lights now seem to be mainstream for growing in winter and out of season, and for bringing on seedlings. If you have bought some and have experience of what is or is not a good buy, I would love to hear your advice.

I am currently looking at something like this:

MarsHydro 600W LED Grow Light Full Spectrum Veg Flower Hydroponic Plant Lamp | eBay

which seems to be on the surface quite powerful and relatively inexpensive compared to some others. But from the blurb they are clearly 'Made in China' (though most are of course).

How close to the seedlings would you need to hang such lights and would they be truly effective in bringing on tomato and aubergine seedlings, for example, or starting early brassica seed?

[arpoet]

You would need to grow a lot of plants to get your money back, in my opinion. But, there again, i am tight Yorkshireman.

[roitelet]

And I am a tight ex Devonian. I can't see the point in the expense of trying to grow things out of season. I know that you will have the pleasure of home grown produce before the normal growing season but at what cost? I do provide heat in an insulated portion of my tunnel from March onwards just to keep the frost off the tomato plants. I have decided that for things that need a very early start and lots of heat I might just as well buy the plants and let someone else go th the expense of starting them off.

[Aberdeenplotter]

I have an LED lamop with built in fan. I don't rate it. I bought it to use in the growing of Leeks and Onions for exhibition but as I say, I don't rate it. I have gone back to my sont agro lamp. Yes its expensive to run and yes it generates a lot of heat but I do rate it

[Alison]

And I am a tight ex Devonian. I can't see the point in the expense of trying to grow things out of season. I know that you will have the pleasure of home grown produce before the normal growing season but at what cost? I do provide heat in an insulated portion of my tunnel from March onwards just to keep the frost off the tomato plants. I have decided that for things that need a very early start and lots of heat I might just as well buy the plants and let someone else go th the expense of starting them off.

I'm with you, one of the reasons I grow my own is to eat in season and whilst it's nice to extend the season a bit with my tunnel etc the thought of the additional power etc doesn't appeal at all and is rather against another of my reasons for growing which is to reduce my carbon impact.

[Potstubsdustbins]

I have no idea on the effectiveness or not of using LED's as grow lights, but about two years ago I started to use them for household lighting. I have recently restocked on bulbs and was amazed at the improvement in the strength of light emission in such a short time.

I imported the latest batch from China as it is a far cheaper option £18-50p for 10 bulbs including delivery. A light fitting in the lounge that used to use 4 50watt bulbs now gives a better light with 4 4watt bulbs. For us using it 8 hours a night that's a saving of 1.472 kilowatts a night. Rubs his hands with glee.

[dogsbody]

I have a solar powered rig for my shed inside light that was running with a 12v dc 9w fluorescent bulb. It had all stopped working and I was blaming the battery - especially when I put it on charge and it wouldn't - until I got the multimeter out and discovered the battery is fully charged and the solar panel was putting out at least 9v on a cloudy day like yesterday. So the bulb needs replacing - best price £16.95 + pp but instead I can get a 10w LED floodlight for around £8 so going to give that a go.

[Bigmallly]

Have a bash at making your own Bertie:

http://www.growfruitandveg.co.uk/gra...hts_69290.html

[Kristen]

LED lights now seem to be mainstream for growing in winter and out of season, and for bringing on seedlings

I don't rate them (or fluorescent tubes) for growing out of season as they have to be very close to leaves. LEDs score in that regard as they are lower wattage and give out negligible heat (tubes don't give out much, and discharge lamps like Metal Halide or Sodium give out loads of heat, have to be a couple of feet away from the plants, but have good canopy-penetration and are thus useful for growing / over wintering taller plants)

LEDs appear to give out less light, to the naked eye, but because they are only giving out light on a single wavelength (usually a lighting rig is a mix of Blue and Red LEDs at a ratio that best suits what the plants need) then there are no wasted wavelengths in the light spectrum (or perhaps better described as the light being more efficiently converted by the plants).

I have fluorescent tubes and Metal Halide, but not tried LED so no point of comparison I'm afraid.

I prefer Metal Halide, but most people disagree with me

Florescent tubes have to be within an inch or two of the seedlings, and as such I find I am having to prop up pots of seedlings in various Heath Robinson ways to get an even "surface" of leaves close to the lights, and as they grow I have to adjust their height. The lighting rig only lights an area immediately underneath it, so a 2' square rig only accommodates plants within a 2 ft square area, with only a couple of inches extra available around the edges. A single MH lamp has fall-off of light strength moving away from the centre, but I can place things that only need "some" light towards the edge, and things that are actively growing in the middle. My MH lamp is 400W and covers about 3ft square, my Tubes rig is 8 x 24W (ie. 192W) T5 tubes and 2 ft square - that's pretty much an identical wattage per square foot of growing area. Distance from plant to MH lamp is much less critical, and is around 24".

T5 tubes are 2280 lumens - 95 lumens / Watt - which is about the same as Metal Halide which is in the range 75 - 100 lumens per watt.

I would expect an LED light rig to be 50% of the wattage, maybe less, of a Fluorescent tube rig, so that would represent a genuine saving on electricity.

Waste/spare heat from my MH contributes to heating my Home Office in winter, and in Spring I move it to a tunnel in the conservatory and it provides additional light supplement (over night) and sufficient heat to maintain 10C on cold nights, so I don't need any additional heating. However, that heat also bugs so they are a problem, perhaps more so, in Winter as in Summer Something to be aware of at least! Another downside of MH is that the bulb performance falls off rapidly, so they should be replaced each season - after 12 months use they will be at around 65% light output compared to a new bulb (but still burning the same amount of electricity)

1W for 12 hours a day for 4 months of the winter is 1.456 kWh and at 17p per unit that is about 24.75p/Watt or £100 for a 400W device.

The lamp you link to doesn't look like a good purchase to me, but as I say I haven't tried LED. I think a lighting rig would be better (than a concentrated how power lamp type), the LEDs would be more widely spaced and the rig then placed within a inch of the seedlings, rather than treated as a high power lamp at a distance with wide-ish coverage. It also looks to be pretty dear - a 2 ft square T5 lighting rig is about £50, and a 400W Metal Halide with reflector and Ballast is £100-£150. For LEDs to be cost effective I would be looking for a 2 ft square rig to be costing £50 or less.

How close to the seedlings would you need to hang such lights and would they be truly effective in bringing on tomato and aubergine seedlings, for example, or starting early brassica seed?

I use my supplemental lighting mostly for Ornamentals; I do put the Tomato plants under them, but only because I have light available. Ditto for Peppers and Aubergines to get largest plants that are growing vigorously at the time I plant them out. Can't see any benefit for Brassicas as I reckon they have plenty of growing season without making an early start.

For those who say "No point" there is a point, for those that want to , to have some Winter Gardening activity

[bravo2zero]

I looked into this a couple of years ago. The plan was to supplement lighting from a skylight in the loft when germinating seed early on. Upshot was i couldnt justify the cost of either bulb/tube type lighting or LED. The pros and cons are that glass based lighting was cheaper than LED but didnt last as long and LED is cheaper to run hence the high cost. To be frank i dont think a few toms a week earlier is worth the outlay and extra work unless you are growing for showing. With regards to spacing if you go ahead i think space and prick out as usual would be good starting point but bear in mind you will have light overhead only so drawing plants to legginess may be an issue.

[BertieFox]

Have a bash at making your own Bertie:

http://www.growfruitandveg.co.uk/gra...hts_69290.html

Thanks for the suggestion, and I think some DIY solution is probably the way to go. I was attracted to LEDS though as I have read they give a much better daylight spectrum and are even cheaper to run than fluorescent tubes, and less fragile.

There was an article recently about a nursery in Japan where they were growing lettuce entirely in artificial light and hydroponically.

All I want to do is give my early seedlings a bit of help, as tomatoes and aubergines always get very leggy early on, and I want something that will prompt them into forming side shoots as early as possible. They need light to do this.

I agree with most of the other comments above though about not growing things out of season just for the sake of it, and I don't want to waste energy; but already using a heated propagator it seems silly not to use a little low power lighting to produce better results.

It can't be that difficult to fix together your own LED assembly and I must have a search on ebay or the web to see if I can get some multi spectrum LEDS I can build into my own unit.

[Potstubsdustbins]

LED-T-MASTER on e-Bay have some good bargains, don't if they will fill your requirements though.