First "season" - indoors!

[bittipippuri]

Not much has changed since the last set of pictures - its been dark and gloomy for the last few weeks, so not much growth has been put on. I'm keeping them alive with the fluoros above the window for now. I have finally had time to order the last few parts I needed to start building my LED lights (transformers etc), so hopefully I'll have a prototype done soon!

I'm seeing some slight yellowing on the lower leaves - what might this be?

Yellowing lower leaves is probably caused by lack of light reaching those leaves. This is quite normal if the lighting comes (near) directly from above from what I gather. If it is just the lower leaves yellowing and dropping off, you should have nothing to worry about if nothing more sinister appears.

[Trizza]

Tonight I set out to build my prototype LED lamp!
The power supplies I'm using are replacement power adapters for ASUS Eee PC laptops - 36W, 12VDC@3A, sourced from ebay for about £7 each. The plan is to use one per lamp, and 6 LEDs per lamp. I couldn't find the right socket locally so I went down to Yleiselektroniikka and bought new plugs and sockets to replace the normal ones. I glued the LEDs to the heatsink using Arctic Silver thermal epoxy, also sourced from ebay, and connected them up into two strings of 3 LEDs each using some thick solid core copper wire.
It all went really well until I realized that I forgot to buy the resistors I needed - d'oh! So I hunted around and found 10*100R 2W resistors, wired them all up in parallel for one 20W, 10R resistor. Just enough for me to run one string at 330mAh with a 3.3V forward voltage - so just over 1W each. I'll be running them at around 3W when I get the right resistors.

Heres the first string hooked up with the ghetto limiting "resistor":


Here it is with the power flowing!


Holy CRAP this thing is bright. I just about shat my pants when I turned it on - I was careful to not look at it yet I'm still seeing stars. And this is only at about 1/3rd of its full rated output :O :O For context - in that picture I'm at the dining table, next to the windowsill which has two long fluoro tubes above it, and with a big halogen lighting the table for soldering work. The LEDs dwarf all that.

Next I plucked Aji Cristal off the windowsill and held the lamp about 40-50cm away:


As you can see, it puts out a tonne of light. It easily outdoes the fluoros above the windowsill.

I'll have to find somewhere to get the right value resistors tomorrow so that I can finish the prototype and try it out at full power

On a side note: Aji Cristal actually has put on some growth since those last pictures, four or 5 new leaves. It has been slow though.

[Trizza]

The prototype is now wired up with all 6 LEDs running through 3.3 ohm resistors - by my calculations that should place it around 700-800mAh, a good operating point for a crapload of light and long life. Its throwing out some amazing light. I'm currently running them in for an extended period of time with a temperature meter attached to see how hot it gets. So far its stabilized at 85 degrees after about 30 minutes. The maximum temperature is 150 degrees so its still well within limits, but a fan is probably a good idea still.

After the test I'll let it cool down and hold it over a couple of plants for a photo shoot!

As for the light quality - it has a definite blue tinge, which should be good for vegetating I guess, and it has a good wide angle range so they should provide great coverage over a few plants. Looking forward to getting it rigged up over some plants:) I'm yet to figure out how to mount them, though..

[Trizza]

Heres a picture taken during the test run. These are super-bright!

[Trizza]

Naga Morich with the new light held about 30cm away - again, all the other lights in the room were at maximum brightness and this just dwarfs them all:


Here's my chilli growing windowsill, with the fluorescent lights above it turned on and the LED lamp about 50cm above the greenery - lots of coverage, and I still have to make four more!

[Fatalii]

Interesting to see more results of that.. 3w leds should so some nice job.

[Trizza]

Any thoughts on how to mount them? It seems a shame to waste the light coming in the window, otherwise I'd move the plants to some shelves and just bolt the lights on.

[Fatalii]

Hmmm don't have better idea than that.... what ever you think, just post it here to give other people nice ideas.

[Trizza]

Ok, took me a couple of weeks to get around to finding a way to mount it!

So, I went down to IKEA and buy one of these for 15€: http://www.ikea.com/fi/fi/catalog/products/10106280
3€ worth of aluminium bar from Bauhaus, some drilling, and a few M4 screws later and we have this:



It clamps right on to the edge of the windowsill, taking up next to no space and solid as a rock I had to add the vertical aluminium bar support because the light would sag down under the extra weight of the heatsink. Better safe than sorry - it has multiple holes for adjusting the height.

Shot of the greenery (once again, this is lit overhead by big fluoros and has a halogen pointing at it too):


Closeup of how I mounted the head. You'll note that I added a fan to the heatsink - with the fan on as slow as it can go, it doesn't even get warm:


Closeup of the vertical bar:


So thats the rough prototype done! Hopefully in a few weeks I'll have time to start the rest of them

[Fatalii]

Nice... it would be good idea to get rid of the halogen tho, produces way too much heat compared to light which quality is bad for your plants.

[Trizza]

The halogen is just the work lamp I use when soldering, its rarely on or pointing at the plants

[Fatalii]

Ahhh, okay!

[Mads]

A lovely project! I've had a bunch of those LED's lying around for quite a while now. Maybe I should start soldering before next season ;-)
Just a little question... Are you using a 12V power supply? And then 3 LED's in series along with the resistors? How come you don't just use a 3V power supply?
Damn. I wish I had more time...

[Trizza]

Yeah, I'm using a 12V power supply with two strings of 3 LEDs with a single resistor per string. I used a 12V power supply because they're readily available on ebay as surplus laptop power supplies - 3V (or actually 3.7V for white Crees) power supplies that would be able to push the amps needed are pretty hard to come by. eg this same rig would need a 3.7V*~6A power supply, without factoring in any safety factor.

A workmate of mine wants me to do a step-by-step guide on building this lighting rig, so once I've got more heatsinks I guess I'll make a how-to thread on building them

I'm definitely seeing accelerated growth! They had almost stopped growing since winter hit, and after 3 days of running the light the Aji Cristal seen on the far right of the group shot has reached the top of its stake, and all the other plants under that light have got a few new leaves.

Fatalii - what sort of day/night cycle do you suggest? I've currently got them on a 12h on 12h off cycle.

[CyberDog]

Many people seems to have good results with a bit longer light period. I'm running 14 hour light period. But it depends a lot of things. Sometimes plants request more "sleep". You notice it when the leafs turn a bit limb.

[tombola]

A workmate of mine wants me to do a step-by-step guide on building this lighting rig, so once I've got more heatsinks I guess I'll make a how-to thread on building them

A little step-by-step tutorial would be highly appreciated! I got very interested indeed, nice work

[zaxxon]

Hi Trizza and congratulations! I do recommend you replace those resistors with a proper constant current LED driver and make only 1 string. You'll significantly increase your efficiency and it will be practically impossible to fry your LEDs. I have some leftover 33.5W 450mA constant current drivers for 20e + shipping

Yeah, I'm using a 12V power supply with two strings of 3 LEDs with a single resistor per string. I used a 12V power supply because they're readily available on ebay as surplus laptop power supplies - 3V (or actually 3.7V for white Crees) power supplies that would be able to push the amps needed are pretty hard to come by. eg this same rig would need a 3.7V*~6A power supply, without factoring in any safety factor.

A workmate of mine wants me to do a step-by-step guide on building this lighting rig, so once I've got more heatsinks I guess I'll make a how-to thread on building them

I'm definitely seeing accelerated growth! They had almost stopped growing since winter hit, and after 3 days of running the light the Aji Cristal seen on the far right of the group shot has reached the top of its stake, and all the other plants under that light have got a few new leaves.

Fatalii - what sort of day/night cycle do you suggest? I've currently got them on a 12h on 12h off cycle.

[Trizza]

Hi Trizza and congratulations! I do recommend you replace those resistors with a proper constant current LED driver and make only 1 string. You'll significantly increase your efficiency and it will be practically impossible to fry your LEDs. I have some leftover 33.5W 450mA constant current drivers for 20e + shipping

Thanks for the offer, but I'm running at significantly higher current - these bin LEDs are rated up to 1A, I'm running around 800mA for ~3W each at the moment. I might build some drivers myself for them.

[Trizza]

Time for an update! First up, Merry Christmas and a happy New Year to everyone

I've been cycling the plants around, giving them each a few days right under the lamp. They've been *loving* the light, I've seen an explosion in growth from all of them.

First, a group shot:


We've got a new kitten here, so we've had a couple of "incidents". Three of the plants are now lacking name tags. Bird's Eye Baby was completely uprooted, losing all but maybe a centimeter of root growth. I repotted it and put it directly under the light, hoping the extra energy would help it survive. A couple of days later I got home from work and one of them ones without a name (I THINK its Black Scorpion Tongue) had been snapped in half near the base, just hanging on by a shred of green - I quickly tied it up to the stake and put it under the light, too. Heres how that break looks:



So there I was thinking those two had little chance to survive, and a couple of weeks later heres what I've got:

A flower bud on "Maybe-Black Scorpion Tongue"! I can quite clearly see purple, live, but I don't yet have a macro lens so couldn't quite capture the colour.

I had been really pleased with Birds Eye Baby's progress, new leaves and shoots forming all over the plant, really going nuts putting on new vegetation. A close look today and:

Four or five flower buds! Miniscule, just like everything else about this cute little plant.

Question time:
- Are chili plants masochists or something?!? The two that are the most tortured are the ones that are flowering!
- AC is just shooting straight up - is there anything I can do to encourage it to put on more leaves at the branch points and spread out a bit? Pruning, perhaps?


Status update on those lamps: I now have everything I need ready to assemble four more lamps, so I'll be digging into that perhaps as soon as tonight

[Trizza]

I was stupid enough not to order those Bio Bizz nutrients earlier, and now it seems like Viherpeukku doesn't stock Bio Grow any more. Any tips for other good places to order it from?