Issues around stretch, stacking, and density with 600W HPS lights.

[craggin]

I've been noticing a pattern from my last 4-5 grows around stretch, stacking, & bud density based on lighting characteristics. I'm using ( 2 ) 600W HPS, but think the concepts still apply regardless of the type of lighting. Of the two lights, one is much older than the other, yet the bulbs in each fixture are identical and the same age/usage.

The pattern around the issue that I would like to resolve is this: The plants under the newer fixture/ballast are generally shorter with much less stretch, better stacking, and denser buds. The ones under the older fixture/ballast stretch a whole lot more, with very poor stacking, and much less bud density. Having always thought that most of those traits are primarily influenced by genetics, I didn't notice the pattern until this current grow. Prior to this current grow, I swapped the placement of the lights within the grow space, and the issue followed the older fixture/ballast.

So, now I'm suspecting the ballast, as the reflector alone seems unlikely to have this much influence. What I'm hoping the community here can help me answer is whether or not ballasts actually can have this much influence, before I drop coin to get a newer light kit matching the newest one currently in use.

I usually scrog/supercrop, so there's only one plant beneath each light. Both plants are (supposedly) the same strain, sprouted from seed. I guess if the genetics from this (local) seed supplier are poor, then that could also be a cause. But, then I probably wouldn't have detected this pattern of irregularity over several grows of different strains.

Ideas? Thoughts? Suggestions?

 

[JimmiP]

How old are the bulbs? If you have used them for 4-5 grows they should be replaced.
Beyond that there are too many variables. You mentioned the reflector, are they both the same? If not, that could be the issue.

 

[craggin]

How old are the bulbs? If you have used them for 4-5 grows they should be replaced.
Beyond that there are too many variables. You mentioned the reflector, are they both the same? If not, that could be the issue.

The bulbs are not that old, but possibly reaching replacement age. I'll try to dig up the receipt so I can confirm. The reflectors are slightly different, but I was under an impression of not being different enough to matter. Maybe it does more so than I thought.

 

[crimsonecho]

also when you say “same strains started from seed” your whole observation looses its meaning in my eyes. try with clones from the same plant, fairly identical clones from the same plant.

 

[craggin]

also when you say “same strains started from seed” your whole observation looses its meaning in my eyes.

Interesting, but I'm not sure I understand why.

 

[Herb & Suds]

Interesting, but I'm not sure I understand why.

The simple fact you believe a breeder can work a line to not get different phenos indicates why you don’t
The only way to compare is using the same exact cut
Mixing phenos and trying to feed the them equally isn’t an actual comparison

 

[craggin]

The simple fact you believe a breeder can work a line to not get different phenos indicates why you don’t

That would be due my lack of awareness, not that I believed it. When I first started growing 40+ years ago, none of the current understanding of cannabis and modern growing techniques that have been perfected since existed yet. I just started growing again about 2 years ago, and I have a lot of catching up to do. I said that only as a basis to start the discussion, so more knowledgeable folks, like yourself, could help me out.

So, no I was unaware that different phenos could/would come from the same batch of seeds. Humbly, I just learned something new today.

This brings up other ideas around what else I could be doing wrong. My hydro system is connected to the same fresh water & nute tanks, so that raises a new concern I never thought of yet.

Thank you!

 

[Herb & Suds]

That would be due my lack of awareness, not that I believed it. When I first started growing 40+ years ago, none of the current understanding of cannabis and modern growing techniques that have been perfected since existed yet. I just started growing again about 2 years ago, and I have a lot of catching up to do. I said that only as a basis to start the discussion, so more knowledgeable folks, like yourself, could help me out.

So, no I was unaware that different phenos could/would come from the same batch of seeds. Humbly, I just learned something new today.

This brings up other ideas around what else I could be doing wrong. My hydro system is connected to the same fresh water & nute tanks, so that raises a new concern I never thought of yet.

Thank you!

Yeah
I heard was a common grow theme
Google didn't do us much good back then

 

[NanoGadget]

The simple fact you believe a breeder can work a line to not get different phenos indicates why you don’t
The only way to compare is using the same exact cut
Mixing phenos and trying to feed the them equally isn’t an actual comparison

To be fair, I have some F6 seeds that show almost no phenotypic variation. Its too bad most 'breeders' these days can't be bothered to take a line past F2...

 

[Dave455]

I've been noticing a pattern from my last 4-5 grows around stretch, stacking, & bud density based on lighting characteristics. I'm using ( 2 ) 600W HPS, but think the concepts still apply regardless of the type of lighting. Of the two lights, one is much older than the other, yet the bulbs in each fixture are identical and the same age/usage.

The pattern around the issue that I would like to resolve is this: The plants under the newer fixture/ballast are generally shorter with much less stretch, better stacking, and denser buds. The ones under the older fixture/ballast stretch a whole lot more, with very poor stacking, and much less bud density. Having always thought that most of those traits are primarily influenced by genetics, I didn't notice the pattern until this current grow. Prior to this current grow, I swapped the placement of the lights within the grow space, and the issue followed the older fixture/ballast.

So, now I'm suspecting the ballast, as the reflector alone seems unlikely to have this much influence. What I'm hoping the community here can help me answer is whether or not ballasts actually can have this much influence, before I drop coin to get a newer light kit matching the newest one currently in use.

I usually scrog/supercrop, so there's only one plant beneath each light. Both plants are (supposedly) the same strain, sprouted from seed. I guess if the genetics from this (local) seed supplier are poor, then that could also be a cause. But, then I probably wouldn't have detected this pattern of irregularity over several grows of different strains.

Ideas? Thoughts? Suggestions?

what are par/ppfd readings under each ?

 

[craggin]

what are par/ppfd readings under each ?

I don't have a good accurate meter, other than an Android app, which I understand them to not be very accurate. But, I took measurements as best I could given current circumstances, and both seemed to be pretty much the same. Both par/ppfd and the K temp. Maybe, this pattern is not really anything other than personal coincidence along with the phenotype variables from seeds. I was rather clueless about that until pointed out to me here, and now after some reading on the subject, maybe it's simply that. I've been thinking of trying clones anyway, now might be the time and do a better comparison to see what's what.

 

[Norml56]

are they both digital ballasts?

 

[craggin]

are they both digital ballasts?

Yes. My suspicion arose from the fact one is over 20 years old, the other is a little less than 2. I must add, the 20+ year old did not see any use until put into service about 2.5 years ago.