Lighting Here's a headscratcher for you

[Banjacked]

Ok, this is the situation. I'm not interested in having huge numbers of plants due to things like space, so have one almost ready and another sprout in a small utility room in my apartment. It isn't as bad as you may think as that's also where the gas boiler for the hot water is so the room has ventilation and the temperature is fairly constant thanks to that boiler firing off whenever we need hot water. In there I have a 4000K 100W equivalent LED bulb in the original ceiling lamp, and I've strung up a couple of other lampholders so I can put "additional lighting" as necessary, like the small 10W actual use (circa 60W if it was a "normal" lamp) LED grow spot over the sprout.

But that's not good enough, imo, I need more efficiency without going silly and getting BFO grow lamps that need more permanent fixing, draw more power, and basically just shine "downwards" on the plant.

That's where my notion of LED grow strips comes in. I ain't talking about the strips that come in pre-made fittings that you can mount like fluorescent tubes, but the strip that comes on a roll so you can, basically, do whatever you wish with it, and that's where this concept comes in.

Take 2m of strip, and fix that to some sort of "dome", spiralling it in so you have a stinkload of small, 120°, lights that end up shining in from all angles around the plant and not just straight down on top, you're directing more light onto all of the plant and since these strips run with a low temperature, with an external power supply so that heat is elsewhere, you can have this dome closer to the plant to concentrate the light onto the leaves more than something just hanging a foot or two above the plant spreading light beyond the area the plant needs. If you think of some sort of high bay reflector lamp, but instead of one big metal halide lamp in the middle the whole "reflector" is all led light, you'll get the idea of what I mean. Doesn't have to be a "dome", it can be any shape you wish as long as it is not "flat and square" so you have the light coming in at all sorts of different angles.

Now, these strips are cheap, I can order a set from China for under €10 for 2m. But has anyone had any experience with these things instead of spots or self-made COB lamps? I mean, €10 is nothing but some advice, if anyone has any, would be helpful before I go and have my little experiment...

 

[Arthur]

I'll tell you straight, if you do this for any amount of time your gonna have grows that you just have to skimp by with what you can fabricate... done it myself...

What your suggesting, may very well grow a plant, but for any kind of quality, there are 3 things that add up more than others.

1 Good nutes
2 Decent air temps/ circulation /rh
(Environment)
3 photons
These are constants for a decent yield of quality cannabis.

I haven't run autos under lights yet, my experience has been indoor with photos, so bear that in mind.

On average, you can figure 50w of light per square ft of growspace. I've heard, and can see the science, that autos can do as well with less wattage, due to running higher hrs of light during flower. How much less? I don't know, there's some very knowledgeable gents and ladies on the site that'll know that better.

I'm just getting a 4x4 set up for autos. With 16 Sq ft, I'll be running 9 cobs @ 50 watts and feel I may be under lit.

In ending, save yourself the frustration! The cash is nothing, 60 days plus of your sweat, love and blood invested only to be disappointed and either spend more money and time, or give up on the "hobby" is not what any of us wanna see.

 

[Banjacked]

PH, temp and circulation ain't a problem, and neither are nutes since I've done my research there too. The seeds get germinated and then put into foot plus wide pots with good, fresh, compost so they never need transplanting. Watering/feeding is done from below so the roots have to work, meaning that there is always a decent root ball and when I see how much my first plant stretched because I was in hospital for 9 days then I know that works, the bloody thing's more like a tree now at the best part of a metre tall which was not the intention.

And that's where we come to the "photons" part. My theory is that there will be plenty of these things from a 3 red/1 blue LED strip with 60 x SMD5050 LEDs per metre arranged to concentrate everything onto the plant itself so as little as possible is "wasted" by, well, just going into the air. I've worked with the "normal" 2400K/3500K strips before in one job I used to do, so I know that the lumens/m is a good figure and if you look here at the second set of tables for standard "white" led strip and not "grow", and 300 led per 5m roll, we're looking at a decent 900+ lumens per metre so, in theory, with the right setup, the equivalent of 50W/sq.ft should be easily achievable if set up properly.

The problem is that the figures everyone uses are for a grow light shining "down" on the plant and not for what will be coming in from different angles at a higher intensity due to being closer to the plant as these strips are relatively new. I see plenty things online but they tend to be contradictory, so some advice would be helpful before I go ahead with my little experiment.

The cost of what I'm looking at is negligible, in reality, so I'll probably try it anyway. But, to me, efficiency is everything which is why "waterproof" strips are a no-no as the added layer to make the strip IP65 mean that you do actually end up filtering out some of the light from the LED's.

Oh, and "giving up" is not an option. Let's just say that there are reasons why I need the weed for medical reasons and this country (Belgium) is retarded regarding medicinal marijuana. Costs of "home delivery" or going to coffee shops in Holland are getting to be ridiculous and you have no idea what you are actually getting wrt pesticides, etc, so I won't be stopping with the growing. As said, things went wrong with my first plant due to being in hospital and it went out of control before going into "survival mode", but thankfully I'm going to get what I hope is a good 15g off of it, which is maybe not much to some people but since that would normally cost pushing €150 then my little €25-30 "investment" is still a winner even though things did go sideways. And since I can't work any more, then I can still have my fun by "experimenting" and then we can maybe gain some more knowledge on matters such as these new-fangled strips which I don't see much about people actually using them and what there is can be contradictory

 

[Arthur]

I see were your coming from, and was not trying to discourage... if it's just an experiment, then all in I say, I know the strip lighting your talking about, I use it under cabnets in the kitchen. I can leave them on 24/7 and not see a $ difference in my bill... I believe, if the strips are the same as the roll I bought, they do come in multiple spectrums. But I think, the issue you will see is these are running a very small led diode. If so these would be the equivalent of some of the early led tech 15 years ago, at the time they were a complete waste of money.... but times have changed, and tech has marched on. Again, was not trying to be snarky or discourage, but I've had grows that were under lit, everything suffered, quality, quantity... if I can save another grower the frustration of spending months doting and caring on a grow only to have a harvest that's so poor it's unsharable in social circles...
And I get the legal issues... I started smokin before Nacy Reagan said just say no... will admit, with my head low and a shuffle of the feet, am enjoying a taste of freedom after 35 yrs in the dark.

 

[Banjacked]

Oh, I understand what you mean about not discouraging me, I've seen plenty posts elsewhere and it seems the critical issue is the distance as some are talking about putting the strips on the walls which does nothing for heat dissipation and it means the strips are too far away to be useful. That's why my theory involves a frame made of the likes of chicken wire, heat can dissipate easier when compared to a "solid" support such as walls or any other "solid" sort of platform, but done in a way that concentrates the LED light better than having anything a foot plus away from the plant meaning that as much of the light, at the right frequencies, goes directly to the plant as possible where it is needed.

It's just a theory just now, but if it works then others doing small grows could benefit from a relatively cheap setup as there are people out there who are discouraged because they think you MUST have expensive specialist lighting that costs a fortune to run. If there's a viable alternative, then we can maybe make some people take the plunge.

 

[Banjacked]

Well, the plunge has been taken with a 5m roll of SMD5050 full spectrum, 4:1 Red:Blue, 60 LED per metre, with power adaptor ordered up. I went for the 5m roll for extra flexibility, a total of 72W for the whole 5m, 14.4W/m. It's costing a wildly expensive €12 with free delivery and will use less than €1.50 of electricity per week at the price I pay for electricity (just under €0.17 per kWh peak hours).

Given that the strip is 10mm wide, you can guess how "compact" a space you can squeeze a fair amount into, we're looking at 3m of strip in a "dome" emitting over 4,000 lumens, up to 7,200 for the full 5m, and since the driver is completely external to the strips the heat should be low enough to place the structure VERY close to the plant with, according to calculations found online, the potential for over 100,000 lux at 4 inches away from the plant with just 3m of strip which I think will "just" be enough for growing a single plant.

Expect a very rough looking construction to appear in the DIY thread when I get my delivery in about 3 weeks.

 

[Arthur]

I think, your # are sound, but lumens and lux are not the values you should be working with.
your should be calculating PAR. Plants don't care how many lumens, but how much photosynthetic available radiation is in each lumen. I believe what your going to see is a high lumen light with a low photon density.
Honestly, I'd really like your idea to work... it would make life a lot more profitable. I'll keep my fingers crossed.

 

[Banjacked]

I think, your # are sound, but lumens and lux are not the values you should be working with.
your should be calculating PAR. Plants don't care how many lumens, but how much photosynthetic available radiation is in each lumen. I believe what your going to see is a high lumen light with a low photon density.
Honestly, I'd really like your idea to work... it would make life a lot more profitable. I'll keep my fingers crossed.

PAR is a bugger because getting an accurate figure from manufacturers is not easy, but, again in theory, at 8 inches away 5m of this strip should be giving me a PPFD of 939 micro mol per wotsit, PAR at 187 watts per sq.m and a DLI of over 60 mol per day if I arrange my "dome" properly to focus as much of the output as possible onto the plant.

 

[Arthur]

Well... I guess florescent lights will grow cannabis... so it will probably indeed grow something. Will be interesting to see how it does.

 

[thetreeman]

If you want to use strips I would go with bridgelux eb 2nd gen, coming out end of dec or samsung hard strips. They can take some power and will perform well. Im way over blurple leds and have no use for anything but white except maybe to supplement red in some instances.