Guide me to the Light....

Ok brothers and sisters, I've been advised by @Rocket Soul to start my own thread so other noobs like myself can use it as a point of reference for a bit of DIY advice. I was advised tag in @cobshopgrow for pointers, and @maddmango, who has helped me a lot by pm.

I'm starting from a point of very little knowledge, and so I hope my little journey will be an interesting one to reflect on in the near future. From me knowing practically nothing except only the most basic things, I hope to have, further on in this thread, pictures of plants in full bloom under whatever you help me to knock together.

So, with that said, here's the bones of it:

My area is a loft/attic grow, my lights will be hanging a foot or so down from the apex on either side.
The floor space is 2.2m front to back, and 2m side to side. I have 1.2m vertical space - This is the point where the actual bar will be at it's highest point. The hanging fittings will be higher up.

I will hang 3 fixtures in there so I have a meter space to get in and work.

The canopy will be scrogged and the screen will start 15 inches from the ground.

At the moment I have parabolic reflectors and 400w bulbs. This isn't a good environment for the plants IMO because the hood traps all the heat. Anyone who has used parabolics before will know it's very difficult to air cool them and, besides, 400w HPS just aren't anywhere near as efficient as the equivalent watts of LED from everything I've read. I can actually go up in wattage to around 450 per fixture based on ambient temps, it's just the environment directly under the hood itself which sucks major ass at the moment.

Hence my switch to LED.

I plan to hang 3 lights in there and for them to be strips. From everything I've seen, they will suit my space better than anything else I've seen yet.

So.. I'm looking for each light fixture to be 90cm wide, by 120cm long (ie the length of the strips) run at around 450w, give or take. And for that to be spread over say 6 strips.

Preferably there will be a gap between the strips to help a bit with light spread, so 2 x strips on a 1.2m heatsink which I'll make out of 3 or 4mm aluminium sheet.

As for everything else, including wiring, drivers, etc etc... that's where you come in.

I've got a basket on Digikey with some Bridgelux BXEB Gen 3 strips, which I've been advised are about the best I can get at the moment. I'm open to any other suggestions obviously.

I've also been quoted some figures from someone on Alibaba for strips which are 56 cm x 7.5 cm, and have 248 diodes per strip, with 8 deep red and 2 far red, which they are also willing to customise to have a different ratio. Price for those is $30 each and shipping is actually reasonable, which it isn't atm for the bigger bar fixtures.

So there we are. Fire away. Let's see what happens.

Peace

I wanna tag in @Barristan Whitebeard @Airwalker16 @bigmikey86 & @christopher jordan
Who helped me a lot in the other thread. Nice one

Coould you maybe draw some stuff of this space? Like how limited you are vertically, if its a traditional roof situattion? You mighhtt be bettter of with somethingg other than strips. Or a combo, hanging boards high in the middle and then strips sorta diagonal along the roof if im imagining this space right. I thought it was a standard 4x4 tent

For a build thats vertically challenged and with strips i would allways rec the vesta strips, dual warm white and cold white channels is 90 cri. They are also cheap, around a tenner for almost 200 diodes. Not as efficient as samsung but they make up for it with running soft and closee and great spectrum for both fflower and stretch control.

Okay, so.. the very tip of the apex is about 6.5ft
Now my lights hang either side, about half way down the slanted sides. Is that a bit clearer?

Just imagine a pitched roof. The lights hang half way down the pitch. Simples.

So the strip itself would be about 4ft from the ground

Rocket Soul said:

For a build thats vertically challenged and with strips i would allways rec the vesta strips, dual warm white and cold white channels is 90 cri. They are also cheap, around a tenner for almost 200 diodes. Not as efficient as samsung but they make up for it with running soft and closee and great spectrum for both fflower and stretch control.

Click to expand...

Ok, so in the spirit of the thread, I'll try and ask all questions that clear any grey areas.

Can Samsungs not be run soft? Why is this strip better for that than the Samsung/BXEB for example?

What would stop me running another board soft and close?

Of course you can run any strip soft but the more expensive it is the worse economics. The vesta is cheap but not great efficiency so it makes sense to run soft and close to the cannopy in order to make up for being somewhat older gen tech. Which seems to go well with your situation.

The real deal is in the spectrum: 5000k / 2700k and the possibility to run both at the same time over the same driver. Imagine it as a strip that could give you the functionality of a MH, a HPS and CMH using the same driver, only requiring to do the mounting work of one strip instead of 3, and youre paying just under 10$ for 20w of chips. Also it is 90 cri, which in this case means all the 3 variants have a bit of extra red and far red which is really nice for both flower and veg. And 5000k
Is a quite extreme veg spectrum for short plants, some plants like indicas cant handle it and just grows into balls of leaves. 5000k 90cri might be a bit less so due to extra red. But basicly its a bit liike having a dialastretcch function.


Also, diode count: each strip has almost 200 dioodes per 2 foot, the eb gen3 has 120 something. Also, measurements: if your bang on 2.2 its hard to fit, including the extra bit for connecting and frameing, 2 x 4foot strips; ebgen 3 are 118cm, while 2xvestas are 112cm.

There arent really any grows to see with these but we tried them and where very happy with flower, compared to 2700k and 3000k in 80 cri.
You could do a similar build with eb gen3 for a bit more cash and buying double the amount of strips of course.

20w is my recommendation most would probably run them at more but i feel with these you can afford to run it soft.

if going vestas may wait for their upcomming new gen.
they should get a led upgrade, basically the same the eb3/slim are using, which gives a nice efficiency bumb.

guess youre aware of it, maybe a good idea to buy over 100 strips at digikey to get the nice pricebreaks.

the vestas are a nice n easy way to play a bit with the spectrum, while not sure if you ever will need that much 5000k if you flower in there mostly.

cobshopgrow said:

if going vestas may wait for their upcomming new gen.
they should get a led upgrade, basically the same the eb3/slim are using, which gives a nice efficiency bumb.

guess youre aware of it, maybe a good idea to buy over 100 strips at digikey to get the nice pricebreaks.

the vestas are a nice n easy way to play a bit with the spectrum, while not sure if you ever will need that much 5000k if you flower in there mostly.

Click to expand...

Hadn't heard that next gen Vestas were imminent. Very cool. What's the word on the drop date?

Rocket Soul said:

Of course you can run any strip soft but the more expensive it is the worse economics. The vesta is cheap but not great efficiency so it makes sense to run soft and close to the cannopy in order to make up for being somewhat older gen tech.

Click to expand...

Hmm. Confused.

So, doesn't the efficiency difference of each bar remain the same as they're dimmed?
I mean isn't a more efficient strip, still more efficient when it's dialed down?
Or Is there a point at which they kind of balance out? If so why is that?

Rocket Soul said:

The real deal is in the spectrum: 5000k / 2700k and the possibility to run both at the same time over the same driver. Imagine it as a strip that could give you the functionality of a MH, a HPS and CMH using the same driver, only requiring to do the mounting work of one strip instead of 3, and youre paying just under 10$ for 20w of chips.

Click to expand...

So this sounds better than running full spectrum LM301/561 or EB.
Again I'm a bit confused. If this is the case, why isn't this a more popular/common choice over those two? What am I missing here?


What's interesting about this quote though is you referenced the CMH.
I've vegged under CMH before and for me it's the best light I've used in terms of how the plant develops re side nodes and branching. Do you know what it is in the CMH spectrum that does that and can most LEDs replicate it?

Rocket Soul said:

Also it is 90 cri, which in this case means all the 3 variants have a bit of extra red and far red which is really nice for both flower and veg. And 5000k
Is a quite extreme veg spectrum for short plants, some plants like indicas cant handle it and just grows into balls of leaves. 5000k 90cri might be a bit less so due to extra red. But basicly its a bit liike having a dialastretcch function.

Click to expand...

Dialastretch how so? By moving the light further away or dimming?
If the colour temp is static, and I had a bushy little indica, how would I adjust the amount of stretch I'm getting?

Rocket Soul said:

Also, diode count: each strip has almost 200 dioodes per 2 foot, the eb gen3 has 120 something.

Click to expand...

This is something which, since I've been reading about LED in general, has had me scratching my head a bit. I alluded to it in the knock off thread.

I don't quite understand why, if the difference in efficiency between certain diodes is only say, 10-20%, a strip with the more efficient diodes is chosen over the one which is less efficient per diode, but which can fit 50% more in the same space.

Like why are so many people about the LM301b/h when it can't fit as many per foot as the 561c, which LEDGardener has as still the most efficient strip P4P?

Rocket Soul said:

Also, measurements: if your bang on 2.2 its hard to fit, including the extra bit for connecting and frameing, 2 x 4foot strips; ebgen 3 are 118cm, while 2xvestas are 112cm.

Click to expand...

Oh no worries about that bit. If we were looking at it birdseye, the third light will be hung so the strips go across laterally, while the two net to each other will have the strips going up vertically, if that makes sense.

Rocket Soul said:

You could do a similar build with eb gen3 for a bit more cash and buying double the amount of strips of course.

Click to expand...

Cash is definitely the least of all factors. I should have put that into my initial post. Shipping from China atm is ridiculous, and to buy pre made from UK or USA makes shipping from China the cheaper option.

I was Quoted over $2000 with delivery by Mejiu for 3 lights last week, put it that way.

cobshopgrow said:

the vestas are a nice n easy way to play a bit with the spectrum, while not sure if you ever will need that much 5000k if you flower in there mostly.

Click to expand...

I'll be going veg to bloom with them mate.

I'm happy with the veg growth I get out of the agro version of the 315cmh tbh. If I can get an LED to match that kind of growth with a better spread of light I'll be more than happy.

Has anyone vegged under a cmh and led, and if so How do they compare?

Humple said:

Hadn't heard that next gen Vestas were imminent. Very cool. What's the word on the drop date?

Click to expand...

@Rocket Soul you where the one spreading the info.

Give me some feedback on these strips as a full cycle light:

https://www.cutter.com.au/product/ssk-1560-3090nic/

Vestas got an "upgrade", the edge version. Different form factor and low efficiency, seems like for home decoration. I assumed they would eventually drop new vestas as they are gen1 diodes and we are now a yeaar into gen3 of ebs, i apologize if i made you think i was sure of it.

Edit: iifc i saw some weird stuff re prices and stock a while back and might have made assumptions.

DukeFluke said:

Hmm. Confused.

So, doesn't the efficiency difference of each bar remain the same as they're dimmed?
I mean isn't a more efficient strip, still more efficient when it's dialed down?
Or Is there a point at which they kind of balance out? If so why is that?




So this sounds better than running full spectrum LM301/561 or EB.
Again I'm a bit confused. If this is the case, why isn't this a more popular/common choice over those two? What am I missing here?


What's interesting about this quote though is you referenced the CMH.
I've vegged under CMH before and for me it's the best light I've used in terms of how the plant develops re side nodes and branching. Do you know what it is in the CMH spectrum that does that and can most LEDs replicate it?



Dialastretch how so? By moving the light further away or dimming?
If the colour temp is static, and I had a bushy little indica, how would I adjust the amount of stretch I'm getting?



This is something which, since I've been reading about LED in general, has had me scratching my head a bit. I alluded to it in the knock off thread.

I don't quite understand why, if the difference in efficiency between certain diodes is only say, 10-20%, a strip with the more efficient diodes is chosen over the one which is less efficient per diode, but which can fit 50% more in the same space.

Like why are so many people about the LM301b/h when it can't fit as many per foot as the 561c, which LEDGardener has as still the most efficient strip P4P?



Oh no worries about that bit. If we were looking at it birdseye, the third light will be hung so the strips go across laterally, while the two net to each other will have the strips going up vertically, if that makes sense.



Cash is definitely the least of all factors. I should have put that into my initial post. Shipping from China atm is ridiculous, and to buy pre made from UK or USA makes shipping from China the cheaper option.

I was Quoted over $2000 with delivery by Mejiu for 3 lights last week, put it that way.

Click to expand...

Vestas offer 2 channels, one warm white with high cri which means extra red, great for flower.
The other is cold white 5000k 90cri.
These 2 channels run independently but they way i configure them i run them on the same driver in parallel. The way i configure the connections is by grouping the channels so that you can send the power down either one channel or half to both. Hence the comparison to 3 different hids, one vegg centric (in reality could be even to extreme to some short plants), one for flower (have seen it myself out grow standard samsungs 3000k 80 cri, lm561c) and one which is both channels which gives you a well rounded fullcycle spectrum. This mid spectrum also runs both channels on half power together dor better efficiency.

I cant answer all questions on why people chose one thing over another really. General consensus after watching loads of blurple leds fail to give results is that photons>spectrum, that theres no special spectrum that can make up for not enough light. So current thinking is highest efficiency of an acceptable spectrum is whats best. I saw a fair few of tests which led me to believe higher cri works better, and in the end if all i have to do is to provide a bit more power then why not go for the better spectrum.
Vestas arent used much for several reasons: low lum/w. They look shitty on the datasheet but thats in part cause its a spectrum: lower green levels than 80 cri means that most people dont understand that their 129lum/w is equivalent to approx 150lum of 80 cri in photons. After that we have a better red leaning spectrum which also seems to influence flower more than what people assume, at least its what extrapolate out of what ive seen in own tests and in side by sides.

People seem to make their choice based on 2 things: photon count per watt; an easy and trustable measure since its the photons and not lums that plants based their photosynthesis. But only watching this number is no good, it doesnt give a picture of how the spectrum will affect growth. Nor does it say anything about spread.
Pricepoints also come in, where you measure efficiency/amount of actual light/price: you can pay more for either more light per watt or more total light at lower efficiency so youre weighing a lot of things. For me ive liked what i saw of the vestas, the grow i built for said: any new flower lights should be this spectrum (2700k 90cri) after comparing to a few other spectrums and builds. Even if the vestas arguably gave less light per watt.
So that coupled with the extra functionality of stretch control has got be a fan of vestas. For a long while it was the only readily available 90cri pcb. Now there are more.

Another thing re why people buy one thing or another is that people tend to follow the general consensus. A few years ago it was 3500k 80cri. But as far as i can tell that was based around the classifications of brightness of the cree cxb3590. Then when crees went out of fashion people played with 3000k and it worked the same butaybe a bit better in flower. Now red supplementation is the craze. This is atleast partially down to how adding reds can lift your photons/w values. Yes, sure it also grows better but i havent seen the conclusive grows that would have me believe its better than an 2700k 90 cri spectrum with decent efficiency.

As you see there is a huge rabbit hole here, and you can research it forever, most of us here are here because of it. But there really isnt one general answer for everybody. And its so easy to to get stuck, and read and read until youre only getting more and more confused. And suddenly you realize summer is here and the build arrives to late. Or that there was one little detail that you missed when you planned your entire system. So my advice: build something to start with and start small. Try to make it opene ended and small, rather than building 4x4 lights build 4x2s that can both hang together or apart.
Dont throw out your hids. More than likely woth led in an attic in the uk you will need the heat. Leds need around 27-30C which wont be easy to achieve with a strip build.
And once you see how it works continue adding on if you like. Or decide, na, good enough.

Very nice post. I think people should read and re-read.

Yea nice post @Rocket Soul Very informative and clears a lot of the debris

I've noticed myself that some things don't add up regarding spectrum and what is "supposed" to be.

Like I say, I looked at the spectrum chart of the agro version of the 315 cmh I thought it looked decent for veg. Turned out to be much better than the Metal Halide bulbs. Something obviously doesn't add up there. The side branching on the plants grown under the cmh is clearly different from stuff grown under halides, and the structure is better too. The issue with the cmh is the focused light. It's really only a 2.5 x 2.5 at most imo.

If you wanna do a test sometime I would suggest to use one and see what you think of it as a veg light, against something LED of a similar spectrum. Like I say it's by far the best for vegging of the lights I've got. You'll probably have a better idea of why that might be than me.

Rocket Soul said:

Vestas offer 2 channels, one warm white with high cri which means extra red, great for flower.
The other is cold white 5000k 90cri.
These 2 channels run independently but they way i configure them i run them on the same driver in parallel. The way i configure the connections is by grouping the channels so that you can send the power down either one channel or half to both.

Click to expand...

Understood. Good system. Not entirely sure I'll need to be this specific regarding veg and flower at this point but at the same time it is very interesting. Like you say, it's a rabbit hole already and I could probably do with one less thing to focus on at the moment in order to just get myself something built. But it is a very useful bit of info, I didn't know you could do that.

Rocket Soul said:

I cant answer all questions on why people chose one thing over another really....

its so easy to to get stuck, and read and read until youre only getting more and more confused.

Click to expand...

That next bit helps a lot to give a good insight into the general consensus and culture of LED growing for people like me who haven't been following it's development and are just trying to get a good general grasp of the situation at the moment.

On the plus side, I'm reading and reading, but not getting more confused. Just recently I was ready to pull the trigger on 3 lights from Meijiu and then focus on building my own for the other side while they were on the way. Then I was quoted over 2 grand so I said fuck that, which made my decision to do a basic build myself.

Rocket Soul said:

Dont throw out your hids. More than likely woth led in an attic in the uk you will need the heat.

Click to expand...

That's one thing I don't need.
I've completely sealed off the attic. It's been my biggest DIY project to date tbh. I've insulated it to where it's another room in the house and then partitioned it so there are two spaces of equal size up there. I can have nothing on up there and, with the intake from the bedroom below, it stay a degree or two lower than the rest of the house.

That space I laid out for you.... there are two of those, so where you say build and see how I feel, that's very much what I can do. I'll be running LED one side and if, for whatever reason, it does't work out, I won't bother upgrading the other side.

It's also the reason why, even though I said I'm not focusing on the money on this build, I'm also not dropping 4K on Alibaba.

Now, I found that cutter does kits... and I'm thinking wtf... did I miss something?

There are ready to go kits available on their site, pretty much exactly what I need, and the shipping is only £80

Can someone just clarify for me what the situation is there?
I feel like there must be some reason it hasn't been mentioned before?

What did I miss?

DukeFluke said:

Now, I found that cutter does kits... and I'm thinking wtf... did I miss something?

There are ready to go kits available on their site, pretty much exactly what I need, and the shipping is only £80

Can someone just clarify for me what the situation is there?
I feel like there must be some reason it hasn't been mentioned before?

What did I miss?

Click to expand...

dont think you missed anything mate, cutter are a good option, just check the stuff you want is already manufactured/instock or be prepared for a couple of weeks wait.
i think some things are built to order, kits might be different?.