Dual Arc And HPS Positioning

[Bobby Smith]

I know there's been a fair amount of threads regarding dual arcs lately, but this is kind of a specific question.

Running four stacked 600s in a vertical cooltube, and have two HPS and two dual arcs and I was wondering what people's opinions were of the best order for the bulbs to be in.

HPS = 90K lumens
DA = 61K lumens

Starting from the bottom:

A) HPS-DA-DA-HPS
B) DA-HPS-HPS-DA
C) HPS-DA-HPS-DA
D) DA-HPS-DA-HPS

If anyone could give a reason why they chose a particular answer that'd be awesome - not sure if I want more lumens (HPS) concentrated in the center (where there's less chance to escape) or the lower lumens of the dual arcs in the center for better light spectrum throughout.

 

[TrichromeFan]

Bobby,
Don't know exactly how much the arrangement matters, but I would think option C or D sounds the most logical. Even distribution with alternating the bulbs. I think if it was a regular grow, I would have the dual at the bottom, for when the plants are small. In your case, I don't think it means much difference in a coliseum grow.

 

[Papa]

+1 for "C"






Papa

 

[Bobby Smith]

Thanks guys, I hope that was your final answer because they're all setup in the cooltubes now.

I'll post a pic tomorrow of this massive cooltube (hopefully in operation).

EDIT: and I totally agree that "C" or "D" makes the most sense for overlapping spectrums, but I was also interested in perhaps seeing the difference in yields/quality between the two halves.

But I think the mixed spectrum is the best call.

 

[lollipopman]

I like c too.. That's what i'd do..

 

[f1ydave]

I agree, alternate them.

 

[motherlode]

cant wait to see this...

 

[lollipopman]

The da are awesome my boy got one and it's doing wonders on his querkle...

 

[Bobby Smith]

"Good Lord, why am I such a fucking moron?"

Grrrrr...............like the absolute moron that I am, forgot to secure the "Tower O' Lights" last night so I went in there today to find it on the floor and (miraculously) only one of the sections was broken (all four bulbs appear to be fine, actually) - two pics are attached.

Have an email into the owner of the company I got it from (will call him shortly if I don't hear back), and hopefully after paying $1K for the cooltube and base, he'll cut me some slack on the replacement piece of glass.

Goddam I'm a fucking moron - not the worst thing ever because the clones won't be ready for another 10ish days, but another $200 charge would've been nice to avoid.

Shit happens, I guess.

 

[lollipopman]

You said grrrr...lmao.. I only thought people around here said that... Side note sorry about ur cool tubes.. Hope dude hooks u up....

 

[Papa]

BS,
i hadn't read through your threads regarding this build until last night.

i am impressed. i'm REALLY looking forward to the grow.

so, i'll attempt to explain my reasoning behind my choice of option "C".

i assumed that even distribution of the light was desired. now, i've read that this is your intention. up front in your last thread you said, "the issue of keeping the lighting intensity consistent throughout the canopy is my biggest concern."

if you were concerned with the intensity of light at points say, 10 feet away from the lamps, the order would not matter. But as you get closer to the lamps, the order of them does have an impact upon what you get. it seems as if your lamps are about 18" apart vertically. so let's think about what light we will get 18" away from the lamps.

options "A" and "B" will provide more intense light where the HPS lamps (with more lumens) overlap and less light where the two MH lamps overlap. the lighting intensity will be less consistent.

options "C" and "D", at 18" distance will have the HPS light overlapping the MH light consistently from the centerline of the uppermost lamp to the centerline of the lowermost lamp. either option will give you equal intensity throughout that distance.

so that leaves the question of having the MH or the HPS lamp at the top (or the bottom). my personal theory is that the MH lamp is providing a spectrum of energy that is more efficiently used by the plant, but the lower equivalent color temperature of the HPS lamps do something to tell the plant that it needs to be putting that energy into flowering. i'm thinking that the use of the HPS in this type of application is more about the "signal" that it's giving the plant . . . and i don't think it needs a lot of light at that lower equivalent color temperature to give that "signal."

so assuming that the upper portion of your array will have a more optimum angle towards your plants (leaves) that this should favor the MH.

am i making any sense about this in words. it would be far easier for me to do this at the whiteboard.






Papa

 

[Bobby Smith]

BS,
i hadn't read through your threads regarding this build until last night.

i am impressed. i'm REALLY looking forward to the grow.

so, i'll attempt to explain my reasoning behind my choice of option "C".

i assumed that even distribution of the light was desired. now, i've read that this is your intention. up front in your last thread you said, "the issue of keeping the lighting intensity consistent throughout the canopy is my biggest concern."

if you were concerned with the intensity of light at points say, 10 feet away from the lamps, the order would not matter. But as you get closer to the lamps, the order of them does have an impact upon what you get. it seems as if your lamps are about 18" apart vertically. so let's think about what light we will get 18" away from the lamps.

options "A" and "B" will provide more intense light where the HPS lamps (with more lumens) overlap and less light where the two MH lamps overlap. the lighting intensity will be less consistent.

options "C" and "D", at 18" distance will have the HPS light overlapping the MH light consistently from the centerline of the uppermost lamp to the centerline of the lowermost lamp. either option will give you equal intensity throughout that distance.

so that leaves the question of having the MH or the HPS lamp at the top (or the bottom). my personal theory is that the MH lamp is providing a spectrum of energy that is more efficiently used by the plant, but the lower equivalent color temperature of the HPS lamps do something to tell the plant that it needs to be putting that energy into flowering. i'm thinking that the use of the HPS in this type of application is more about the "signal" that it's giving the plant . . . and i don't think it needs a lot of light at that lower equivalent color temperature to give that "signal."

so assuming that the upper portion of your array will have a more optimum angle towards your plants (leaves) that this should favor the MH.

am i making any sense about this in words. it would be far easier for me to do this at the whiteboard.






Papa

Thanks Papa, really appreciate the kind words - also, I owe you a beer for being one of the few to actually take a look at that buildout journal :)

And yeah, makes perfect sense regarding alternating the lamps - was pretty certain before I asked that "C" or "D" was the best option, just wanted to get some input (like you've provided) possibly explaining why that was so.

As far as the difference between "C" and "D", you kind of lost me there (I'm admittedly mildly retarded) but I'm just gonna take your word for it :smoke

You said grrrr...lmao.. I only thought people around here said that... Side note sorry about ur cool tubes.. Hope dude hooks u up....

He said he would - since I only need the replacement glass, it's gonna be $40 + $15-20 shipping - beats the shit out of the $240 price for a whole new section :rastadancing:

 

[f1ydave]

Bobby - That is an awesome replacement price. I know too many people who put things up to see them up and walk away and forget they aren't attached, lol. I can't wait to see the build up and mounted! Give us some pics before you plant!

Papa, I am not aware that certain types of lighting make a plant think its veg/flower. While it is true that the plants use certain types of light more efficiently during the different stages of life, I am only aware that timing actually triggers this.

I have not done my own trial and errors around this. Are you suggesting that using red spectrum bulbs can force a flower even at 18 hour a days?

 

[Bobby Smith]

Bobby - That is an awesome replacement price. I know too many people who put things up to see them up and walk away and forget they aren't attached, lol. I can't wait to see the build up and mounted! Give us some pics before you plant!

Papa, I am not aware that certain types of lighting make a plant think its veg/flower. While it is true that the plants use certain types of light more efficiently during the different stages of life, I am only aware that timing actually triggers this.

I have not done my own trial and errors around this. Are you suggesting that using red spectrum bulbs can force a flower even at 18 hour a days?

Yuppers - $40 for the glass, $20 for shipping, will be here on Wednesday the 17th - not a biggie because it'll be at least that long until I nurse these clones to a level of health where I'm okay blasting them with 2400 watts (obviously I'm gonna stagger the lights the first few days to do my best to avoid lumen shock).

Yeah, pure stupidity on my part - thought I could let it stand by itself overnight before I installed it correctly by attaching it to ductwork and reinforcing it - dar dee dar.

As far as the lighting goes, I don't know if it's true but it's "claimed" that the blue spectrum of MH more closely resembles the noon sun on a summer's day, whereas the reddish hue of HPS is more like a setting sun in autumn.

And no, I've vegged 18/6 under HPS (to slow down growth) and it doesn't induce the plants into flowering.

 

[Papa]

Are you suggesting that using red spectrum bulbs can force a flower even at 18 hour a days?

no, not at all. i'm saying that generally, the highest color temperatures in sunlight occur around june, and as the year progresses, and the angle of the sunlight changes, the sunlight has more atmosphere to penetrate which lowers the relative color temperature.

years ago, someone told me that plants can sense this shift and they respond to it.

is it much? i dunno. its it measurable? i dunno. but it is something that occurs in the natural environment, and might possibly be another signal that plants interpret to know what part of the reproductive cycle they should be in.

i believe jack is trying out HPS and HPS/MH combinations in one of his grows. maybe some day one of these guys with a big room can try several different combinations within the same room with the same strain and we'd get some actual data to work with. until then, it's just theory.





Papa

 

[Bobby Smith]

Update

So, got the glass delivered Tuesday and glued it in Wednesday - pretty comparable to the work of a first grader, but it was still challenging for me and I managed to make it look sloppy :boogie:

Also, when removing broken glass, just because you're wearing rubber gloves doesn't mean you can go at it with impunity - have a pretty nice gash in my thumb.

Cut a piece of plywood and added self-leveling legs to it, then duct taped that to the base - adds TREMENDOUSLY to the stability, and I'm gonna email the owner of Octagon Hydro and recommend he include one with every Vertitube - costs $4 or something, and it stabilizes it SO much better it's silly.

Haven't hooked up the wiring yet because it looks like one of the included cord sets might not be long enough to reach, so I'll either have to move one of my ballasts, find an extension cord thingy for ballasts, or strip one of my 15' mogul/cord sets and use that instead.

Any questions/comments, just ask - it's duct taped to a hook on the ceiling right now, so it's pretty frigging sturdy - if this one falls overnight, I clearly need to find a new hobby......

 

[Bobby Smith]

BS,
i hadn't read through your threads regarding this build until last night.

i am impressed. i'm REALLY looking forward to the grow.

so, i'll attempt to explain my reasoning behind my choice of option "C".

i assumed that even distribution of the light was desired. now, i've read that this is your intention. up front in your last thread you said, "the issue of keeping the lighting intensity consistent throughout the canopy is my biggest concern."

if you were concerned with the intensity of light at points say, 10 feet away from the lamps, the order would not matter. But as you get closer to the lamps, the order of them does have an impact upon what you get. it seems as if your lamps are about 18" apart vertically. so let's think about what light we will get 18" away from the lamps.

options "A" and "B" will provide more intense light where the HPS lamps (with more lumens) overlap and less light where the two MH lamps overlap. the lighting intensity will be less consistent.

options "C" and "D", at 18" distance will have the HPS light overlapping the MH light consistently from the centerline of the uppermost lamp to the centerline of the lowermost lamp. either option will give you equal intensity throughout that distance.

so that leaves the question of having the MH or the HPS lamp at the top (or the bottom). my personal theory is that the MH lamp is providing a spectrum of energy that is more efficiently used by the plant, but the lower equivalent color temperature of the HPS lamps do something to tell the plant that it needs to be putting that energy into flowering. i'm thinking that the use of the HPS in this type of application is more about the "signal" that it's giving the plant . . . and i don't think it needs a lot of light at that lower equivalent color temperature to give that "signal."

so assuming that the upper portion of your array will have a more optimum angle towards your plants (leaves) that this should favor the MH.

am i making any sense about this in words. it would be far easier for me to do this at the whiteboard.






Papa

Papa, I'm gonna go take some measurements around the cooltube at different points, specifically focusing on the difference between the output of the DA and HPS bulbs at 18" away (have a 16" ruler, and figure it's 2" from the glass to the bulb, so call it 18").

Obviously, I've wired it all up and it's running (I'll get a pic or two of that as well).

 

[Bobby Smith]

So, I'm Thinking Of Dropping The Dual Arcs

Took readings from 18" from the BULB (16" from the cooltube) from all four directions off of each bulb (at 90 degree angles, but directly perpendicular to the middle of the bulb), with four bulbs, for 16 total measurements.

^^^If this explanation is confusing, lemme know.

The bulbs (working from top to bottom) are dual arc, super hps, dual arc, and super hps (all used for <1 hour total).

The dual arcs put out 61K lumens and the HPS 90K, tested and verified bare bulbed with my light meter a week or two ago.

Location One (from top to bottom):
2340
3930
4050
3920

Location Two (same top to bottom):
2520
3770
3930
3840

Location Three:
2560
4210
3370
3850

Location Four:
2480
3650
3560
3810

Average:
Top Bulb (DA) - 2475
Second Bulb (HPS) - 3890
Third Bulb (DA) - 3727.5
Bottom Bulb (HPS) - 3855

Conclusion - without a doubt, swapping out the top dual arc for an HPS (and possibly the other dual arc as well, still undecided on that) - I just can't justify that amount of light loss for the top-most plants, regardless of how much better the spectrum may be - I'm not sure my canopy will even get to 18" from the bulbs (it prolly will, but it could stay in the low 20s easily as well), and 2500 foot candles ain't cutting it for me - I'll take 3500 foot candles and a shitty spectrum all day in that situation.

P.S. - don't forget to wear your welding goggles when dealing with vertical bulbs, people.

EDIT: I guess I could swap the top two bulbs and have the dual arcs in the middle and the HPS on the outsides - methinks that would give me the most even canopy lighting (as even bulbs will certainly favor the middle) as well as giving me a better chance to see the true "effect" of the dual arc spectrum on the plants in the middle vs. the plants on the perimeter when both sets are receiving a comparable number of footcandles..........thoughts?

 

[UCtestn]

^ Cool!

 

[TrichromeFan]

P.S. - don't forget to wear your welding goggles when dealing with vertical bulbs, people.

EDIT: I guess I could swap the top two bulbs and have the dual arcs in the middle and the HPS on the outsides - methinks that would give me the most even canopy lighting (as even bulbs will certainly favor the middle) as well as giving me a better chance to see the true "effect" of the dual arc spectrum on the plants in the middle vs. the plants on the perimeter when both sets are receiving a comparable number of footcandles..........thoughts?

You got it right on the eye protection. I have dark shades and a hat, and that is only good for looking away from the bulb. I definitely have to pick up some like those sweet ones you got there.:rauch08:

On the spectrum and lumen thing, I think that you have got to try it with putting the 2 dual arc's in the middle.

I would be curious on a re-read with the meter with that configuration.

-TF