Topic: Anyone else started yet?

[mike77]

Started my 2011 chinense varietys mid November under artificial light and they are doing quite well.
Has anyone else taken the plunge?

[Digeroo]

Well done. 

I am interested in your artificial light.  Can you give us more details of what you use.  Does it cost quite a bit to run? 

[mike77]

I am using a blue 125w cfl (envirolite) Im running it 18 hours on and six off and when the rest of the seeds come up I will be using two of them with a reflector like this

(roughly one meter long)

It may look overkill but it's got to cover quite a few plants!
As for the electric I wouldn't have a clue but 2x125w bulbs shouldn't be much ;D

[Vinlander]

That's a lot of light - the equivalent of 1250W of incandescent bulbs (without the killing heat or stunning cost).

I'm not surprised the plants are doing well!

They are also very, very expensive bulbs - though they are the best.

Have you tried it with just one?

One would be the equivalent of 7 x 20w (100W equiv) CFLs, and I got quite good results last Jan/Feb with just 2 x 20W CFL (daylight white) over a 50x75cm propagator.

I might have gone for double (3 or 4 x 23W CFL) if I'd started in Nov - but I think you can still get 23W CFL from Wilko at £1 each - so it would only cost 3 or 4 quid to set up.

At Poundland in October they were offering 6 x 11W CFL for £1 - though it's a lot more wiring!

I'd say daylight white CFLs do the same job for 10% the setup cost, though they will take 10% more power to provide the same light in the colours that count. Only the extra heat might be a problem if you carry on into a mild spring.

Needless to say you need a good, sensitive RCB breaker for any homemade installation.

Cheers.

[chriscross1966]

I',m about to start off with artificial light, trying on onions first but if it works out then chillis would be next along with aubergines.... I'm building the lights out of high-efficiency LED's and dedicated drivers.... more expensive up front (and fiddly and it helps that I have a degree in both electronics and biology so I can translate gobbledigook physics into similar biochemistry) ..... looking at the absorption curves of chlorophyll and the emission frequencies of some shockingly bright LED's it should be possible.... trouble is if you ask around online then all you get is stoners who either know no physics, or no biology (or usually neither) and quote garbled hearsay like it's fact.... The signal to noise ratio is appalling..... trouble is if they were any good at it they'd be too stoned to post anything online...... I even had one pillock trying to explain the reason why you had to use Luxeons was because they pulled 350mA and that made them more efficient.... it's why you avoid them because it makes them inefficient from the thermal problems it causes... you want the same LED cavity physics  in smaller sizes so you don;t have the heat problem and the whole thing runs cooler at the wafer without heatsinking...... Cost me about thirty quid to do three seed-tray sized propagators and it'll pull about 30 watts total....

[aj]

I'll be starting mine soon, under no more light than a big window affords.

My basil sown a couple of weeks ago is up - and my onions are being started in punches from today onwards.

[davejg]

Any chance of some diagrams? would like to have a go at building one myself.

[Vinlander]

I even had one pillock trying to explain the reason why you had to use Luxeons was because they pulled 350mA and that made them more efficient....

There is a serious and sudden drop off in LED efficiency at high currents - but it's high currents per square mm of junction so it depends on the device and its heatsink.

However most devices are rated to the point where the efficiency has dropped to half the best figure - it does mean that pushing LEDs to save installation cost is counter-productive...

to the point where dirt-cheap CFLs start to look like a Very good compromise.

[chriscross1966]

I even had one pillock trying to explain the reason why you had to use Luxeons was because they pulled 350mA and that made them more efficient....

There is a serious and sudden drop off in LED efficiency at high currents - but it's high currents per square mm of junction so it depends on the device and its heatsink.

However most devices are rated to the point where the efficiency has dropped to half the best figure - it does mean that pushing LEDs to save installation cost is counter-productive...

to the point where dirt-cheap CFLs start to look like a Very good compromise.

exactly my point re: Luxeons.... there's four junctions on the 10mm units I'm using, would have preferred the same thing but with one junction per in 5mm tbh....I've been assuming that lux-absorbed-per-watt LED's should win hands down cos all the light is absorbed (the plants look black under the lights which means they're absorbing all of it so there's none to reflect)....

[Vinlander]

I'm about to start off with artificial light, trying on onions first

Just had a thought - onions are fairly hardy and have a very efficient storage organ - have you thought of putting them in a cold greenhouse/frame surrounded by mirrors (bacofoil)?

We all know that the sun on a good day can make up for quite a few dull ones.

It's something I intend to try - why waste precious sunlight on all that bare soil round the polytunnel? It's only speeding up the weeds...

Cheers.