Why go 24 hours lights on??

[Unclepeter]

You however did erase your posts when you deleted your account here as Kopite. Just to come back as uncleclepter, with the same attitude you had as Kopite.

nope try again. but prob best to ignore each other. by the way theres been many other names other than unclepeter.

When I proved you wrong about your claim that cannabis is an obligate outcrossing genus, that was the nexus of your animosity toward me. You still haven't let it go that I proved you wrong many, many months ago; that's pretty damn sad, man. You should try to like when you are proven wrong, then you can become right.

thanks for the laugh. I still got all the posts though(below are your words).

I didn't claim you were wrong without a doubt. I honestly didn't agree with what you wrote until I read your reference, the problem was one of definition, and is why it's important to post references in cases like these (or when it's requested of you, I, or anyone else):

In common definition (at least for cannabis folks) outcrossing is breeding (for example) two different varieties together, and incrossing would be breeding the same variety to itself (ala inbreeding, for example to make an IBL). The actual definition of outcrossing is what you are using, that which is not selfed, however, because both you and I assumed each other were on the same page (and we were not) I didn't agree with your statement; there is nothing wrong with honesty and polite disagreement. Now that I read your reference to "Advances in Hemp Research", and see that you are using proper definition of outcross (at least for plant breeding) I agree with you 100%.

That said, I don't agree with the claim in Advances in Hemp Research in terms of cannabis being an obligate outcrosser, the reason being obligate is a very strict term, and because cannabis can self pollinate in nature (albeit it's not common) would in my mind make cannabis a facultative outcrosser when defining outcross as not selfing.

 

[Bong Rippington]

Thanks for the information Spurr. You've definitely got me thinking about upgrading my lights, and double checking my distances to canopy.

Quick noob/laymans question - Is it even remotely possible to reach optimum DLI with 250 Watters (MH)? I would try to figure out the calculations but I dont currently have a spare $200 to shell out for a proper photon meter to measure for myself.

 

[mad librettist]

heya spurr,

whatabout reveg, and also cloning.

is there any info out on the optimal light cycle for those?

btw I'm running a 600w 18/6, because a while back you wrote they are the most efficient. Is it still true?

 

[bobman]

when i first started this game i was at 24/0 .. at some point i switched to 18/6 and have stayed there ever since .. just seems like the girls like it better to me ...i will go with 24/0 to regen a cutting that was in flower but only for as long as it takes her to change her mind. we all do things a little different which is one of the cool things about this sight ... but i gotta admit it is fun watching folks like SPUR "bookslap" the shit out of some other folks. but then i only enjoy it because it is an entertaining way to pick up some great info. gotta like someone who throws down the bibliography to prove a point instead of just repeating what they have been repeating because it seems to work for them. it's in our nature to not see eye to eye but IMHO the guy with the facts does better in the end.

if you read the referenced material it does not prove his point either. nobody is going to know until there is a study to prove the point one way or another.

 

[NFR]

I've done enough of both 24 and 18/6 to know how much the 24h cuts my Veg time. People argue with me all the time but none of them argue from any kind of experience. They have always done 18/6 or some other length of darkness.

During the hottest times of the summer I will be forced to shut the lights off during veg.

 

[greenmatter]

if you read the referenced material it does not prove his point either. nobody is going to know until there is a study to prove the point one way or another.

i was not taking a position on this one. the point that i was trying to make was that it's good to see people break out their sources to prove a point. was not siding with anyone. like you say until there is a study to prove this one way or another we won't know for sure. in the meantime i'm gonna go with what works for me and keep reading

 

[spurr]

Thanks for the information Spurr. You've definitely got me thinking about upgrading my lights, and double checking my distances to canopy.

Quick noob/laymans question - Is it even remotely possible to reach optimum DLI with 250 Watters (MH)? I would try to figure out the calculations but I dont currently have a spare $200 to shell out for a proper photon meter to measure for myself.

I doubt you can reach optimum DLI with a 250w MH. What brand and model do you use? I have a 250w MH (self-ballasted) here, I could buy a new lamp and test the irradiance for you; then you could calculate DLI according to how long you want to use it (per day). It would not be very accurate irradiance figures due to difference between our setups, but would be close enough. How far from the canopy do you keep your MH?

I could test late next week or early two weeks from now, using the Licor quantum sensor (it's much more accurate than the cheaper quantum sensors).

 

[spurr]

heya spurr,

whatabout reveg, and also cloning.

Do you mean daylength? For reveg I would use 18/6 if I was using high irradiance (umol/area/second). For cloning I use either 18/6 or 20/4; during cloning high DLI is not important, nor is high irradiance, lower irradiance is better (ex., 200-300 umol/area/second).

is there any info out on the optimal light cycle for those?

Not specifically that I have found, for reveg all we are doing is affecting Pfr reactions to stop flowering and start vegetative growth.

btw I'm running a 600w 18/6, because a while back you wrote they are the most efficient. Is it still true?

Refresh my memory, to what aspect (type) of efficiency was I referring? I don't recall writing 600w are most efficient as a rule. Efficiency can mean a few things, I am not sure what 'type' of efficiency you/I were referring to.

 

[bobman]

i was not taking a position on this one. the point that i was trying to make was that it's good to see people break out their sources to prove a point. was not siding with anyone. like you say until there is a study to prove this one way or another we won't know for sure. in the meantime i'm gonna go with what works for me and keep reading

Yes, but the referenced material does not prove the point. There is a scientific study, that I am sure spurr has read but does not reference, that says rooted marijuana clones grew fastest under 24 of light for the first few weeks. But that was just an observation and not the point of the experiment, so we do not know the variables. There are so many variables in this agruement it hard to apply to every situation. Its my belief that if you are growing in 90 day cycles, 30 days of veg from a rooted clone and 60 days of flower that 24/7 of light will get those plants biggest without any loss of vigor. I also believe there is a diminishing return from 24/7 after so much veg time. Again we are not going to know until somebody does a study. Until then we can only go by what we observe.

 

[spurr]

Yes, but the referenced material does not prove the point.

What point(s) are you still hung up on? Ideal figure for DLI? Or are you trying to claim DLI doesn't matter?

There is a scientific study, that I am sure spurr has read but does not reference, that says rooted marijuana clones grew fastest under 24 of light for the first few weeks. But that was just an observation and not the point of the experiment, so we do not know the variables.

I know of no such study, if I knew about it I would have posted it. I do not only post studies and works that back up my points, that would not be very unbiased of me.

Please do not assume you know what I have, and have not read, nor do not assume you know what I would and would not do. If you know of such as study, why did you not upload it?

There are so many variables in this agruement it hard to apply to every situation.

I disagree, there are not an unruly number of variables, they can be accounted for and worked into various studies. Some of the key variables are instantaneous irradiance, VPD, Co2, nutrients, plant age and plant ecotype heredity. It's not hard to do such work, all it takes is the proper analytical equipment. Once I have a good Chl fluorometer I can start testing. Albeit using Pn/Chl fluorormeter chamber would provide more accuracy and insight/data; but the that is much more expensive and I can't afford to buy it until at least the end of this year.

It would be great if Gypsy would setup a fund where people can donate money to buy needed equipment. Then I, and a couple of others here, could use the equipment to get answers sooner rather than later. The Pn/Chl chamber is ~$50k...

Its my belief that if you are growing in 90 day cycles, 30 days of veg from a rooted clone and 60 days of flower that 24/7 of light will get those plants biggest without any loss of vigor. I also believe there is a diminishing return from 24/7 after so much veg time.

You apparently still do not understand it's not about hours per day, it's about photons per day (granted, we want at least ~16 hour daylength); we don't need a study for that fact.

Again we are not going to know until somebody does a study. Until then we can only go by what we observe.

It's going to take more than one study, if I had the needed tools I would be planning the studies already.

I have not yet emailed Dr. Mahmoud A. ElSohly to inquire about DLI. That is, if he has studied (or knows of studies about) ideal DLI, like he has studied ideal irradiance (as umol/area/second), for cannabis. I will email him soon, this week I will make time.

 

[mad librettist]

thanks spurr, I'll put my cuts under 18/6 instead of 24/0.


I think your comment on the 600w was in a contentious thread about LED's...

 

[bobman]

No I understand what your saying about light. But like you just said you do not know for sure so you can not say for sure. I will search for that study and link it. It came up in the first few searched results when I was reading a few months back so I assumed you saw it with all the reading you have done. That was very unfair of me to say, so I am sorry. I will link it in the next few days, probably tomorrow. I just do not have time right now.

 

[GIS]

What do people think about lighting schedule for clones that are rooting? This is the main reason I keep the flourescents on all the time with my vegging plants, because the clones are in there too and I always have read that clones need 24 hrs. Anyone have any experience with rooting in 18 hrs light compared to 24 hrs light?

 

[spurr]

No I understand what your saying about light. But like you just said you do not know for sure so you can not say for sure. I will search for that study and link it. It came up in the first few searched results when I was reading a few months back so I assumed you saw it with all the reading you have done. That was very unfair of me to say, so I am sorry. I will link it in the next few days, probably tomorrow. I just do not have time right now.

 

[spurr]

What do people think about lighting schedule for clones that are rooting? This is the main reason I keep the flourescents on all the time with my vegging plants, because the clones are in there too and I always have read that clones need 24 hrs. Anyone have any experience with rooting in 18 hrs light compared to 24 hrs light?

For cloning I use either 18/6 or 20/4; during cloning high DLI is not important, nor is high irradiance, lower irradiance is better (ex., 200-300 umol/area/second). I find rooting isn't any faster, or better, under 24/0. Granted I have not tested the irradiance, but I plan to the next time I take clones. I use a custom designed and built 'aerated-aerocloner', my aerocloner is the same design pioneered by Dycans, but I also add a big air pump to increase the DO in the water to much higher levels.

Under 18/6, 20/4 and 24/0 I get roots starting to form in 3-4 days without using any rooting hormones. When I do use rooting hormones (from Super-grow) the roots form (a bit) faster and are greater in number and size.

 

[mad librettist]

I am trying something new (to me) - a flat filled with napa 8822, just the larger chunks, with a big plastic dome. I have the 8822 moist, but no standing water. I will use a widger to transplant when the time comes.

You can pour a crazy amount of water into this stuff and still not have any standing at the bottom. Crazy I say!

 

[WoodElephant]

Only read a small amount of this thread, but subbing so I can read more at my leisure.

LOVE the info you're putting on here, spurr. Out of curiosity, do you have any scientific training (Ph.D, M.S., etc.)?

 

[Bong Rippington]

I doubt you can reach optimum DLI with a 250w MH. What brand and model do you use? I have a 250w MH (self-ballasted) here, I could buy a new lamp and test the irradiance for you; then you could calculate DLI according to how long you want to use it (per day). It would not be very accurate irradiance figures due to difference between our setups, but would be close enough. How far from the canopy do you keep your MH?

I could test late next week or early two weeks from now, using the Licor quantum sensor (it's much more accurate than the cheaper quantum sensors).

Thanks for the reply. I'm using a magnetic ballast with a standard 250w MH Bulb from Phillips I think. I just started a new grow from seed using a 20/4 schedule and so far i'm very happy with the results. I've been keeping the tops of the plants no more than 12" away and in most cases probably in the 8-9" range from the bulb underneath a reflector hood. I've been trying to work off of this old chart that has been passed around for ages:

http://i120.photobucket.com/albums/o197/dirt_cheap_goods_2006/mh-chart.jpg

I've quickly come to realize that on my limited number of previous grows I had been keeping my lights wayyy too far away from the canopy. Reading about inverse-square made me want to cry. I'll definitely be upgrading to a 600W HPS for flowering. Anyways - Thanks again for the great information. I've got HIGH hopes for my new grow.

 

[MasterBudGrower]

Use what works for you

Use what works for you

It's not whats better, Its what works better for you. So that is that. I go 24 on clones and seeds right from start. don't have to deal with timer and it works very well.

 

[R3ZIN]

Seriously, 15 pages of dialogue on this matter that's truly rofl.

Thanks Spurr for backing up your point of view with some solid science.

Anyone want to summarize what the end conclusions are ?