Question on Lighting and Transitioning to Flower

[Straycat]

Hey all: I have a couple quick questitons regarding a transition issue. I currently have a few plants two months old and ready for flowering. I have switched my lighting (2x1000w) from MH to HPS and want to switch to 12/12 lighting schedule. I currently have a hydroponic drip system.

My questions are:

1) Until I get the room light leak free and get the nutes changed will it hurt the plants to run two days (three at absolute most) on 24/7 HPS (continuous lighting)?

2) I have some fresh clone transplants. That is they rooted over a ten day period and are now in their first week of a little ebb 'n' flow system. Will they be allright for three days under 24 hour HPS lighting? Would it be alright to have the fresh clone transfers on a 12/12 lighting schedule for three days?

You can imagine from the question I only have the one room right now and has to be committed to flowering. The clones will have a new home in two to three days but unfortunately no sooner. I thought since the clones are basically adult plants I didn't want to take the chance of them beginning flowering so my decision was to keep the lighting 24/7 for three more days but under the HPS lighting.

Any answers will be much appreciated. THX

 

[Grower13]

1.I don't see a problem as long as you have not already switched them to 12/12.

2. keep the clones under 24/7...... don't want to confuse them.

IMO when plants are allowed sit in the dark 12 hours at the time......... they change what their life strategy is in a 3 days.


goodluck!

 

[Hick]

everything should be just fine, as long as the light is distanced sufficiently to not burn/stress the cuttings..
BUT... 3 says of 12's might influence flowering of already mature cuttings. I jus doubt that 3 days is going to be a huge factor. Maybe those could be placed under a cfl, tube shop light, or even the window sill for an additional few hours of light p/day ??

 

[BBFan]

Many people veg under HPS. You may even like what happens! You can run them under 24/7 hps for as long as necessary.

You also don't need to switch nutes when you switch to flowering.

My experience in side by side mh vs. hps comparisons was the mh had tighter internodal growth but the hps plant developed much larger fan leaves. Both results were ultimately equal in terms of yield.

 

[Hushpuppy]

I would disagree with yu BBFan on the switching of nutes. For those of us (like yerself) who really like to micro-manage our grows, we tend to "tweak" different parts of the process to maximize efficiency and yeild. For the beginner or novice grower, it would be easiest to switch nutes with the lighting switch. MJ in veg needs more Nitrogen with a little Phospherous and potassium (and other trace minerals that are with the standard nute program), but when in flower, MJ needs the nitrogen turned way down and the P and K turned up. Following the standard commercial nute schedule that comes with a given brand of nutes is the simplist way to go for beginners. Timing for this switch is not critical but is easiest to follow the light schedule, JMO.

 

[Locked]

I always veg under a 24-0 light schedule...no matter if I am using HO T5's for veg or back when I vegged with HPS. I was never a fan of vegging under MH.

As for switching nutes...I use GH 3 part and provided my plants are nice and healthy going into the flip I switch to the flowering mix as soon as I flip my lights to 12-12.... If they are a lil lacking in N I do a week of a transitional mix with some extra N. Once they are in flower fully they only get two parts the rest of the way unless they get N deficient. Then I hit them off with a lil grow nutes for a feeding or two.

Jmo

 

[BBFan]

I would disagree with yu BBFan on the switching of nutes. For those of us (like yerself) who really like to micro-manage our grows, we tend to "tweak" different parts of the process to maximize efficiency and yeild. For the beginner or novice grower, it would be easiest to switch nutes with the lighting switch. MJ in veg needs more Nitrogen with a little Phospherous and potassium (and other trace minerals that are with the standard nute program), but when in flower, MJ needs the nitrogen turned way down and the P and K turned up. Following the standard commercial nute schedule that comes with a given brand of nutes is the simplist way to go for beginners. Timing for this switch is not critical but is easiest to follow the light schedule, JMO.

I agree with you Hushpuppy, as a simplified method of applying nutrients, following the light schedule to determine appropriate nutrients is easiest to implement. However, to delay a lighting switch based on nutrients as the OP stated:

1) Until I get the room light leak free and get the nutes changed will it hurt the plants to run two days (three at absolute most) on 24/7 HPS (continuous lighting)?

is simply not necessary, and in fact (unless trying to minimize stretch), many would advise continuing to feed vegetative nutrients during the first 2 weeks of switch to ensure the plant will have sufficient nitrogen to last through flowering- particularly with long flowering sativas.

So again, I agree that it's easier for a novice, but it certainly isn't required and most likely is not the best course under good conditions, regardless of what the schedule says.

 

[AlkaloidContent]

You can deff veg under any source of light for 24/0 and it will not harm the planbt whatsoever.

The only thing one has to think about also is that the reason the plant begins to flowers when mature with the change in lighting is because the chemical process changes in the plant. If you suddenly go to 24/7 right as its time to 12/12 it, it may take a little longer for the flowering and sexing to show. Since the buildup of the chemical that inhibits flowering when days are still too long is higher than it may get in your plant now. As soon as the lights kick on it begins to promote this chemical, when the lights go out it breaks back down.

This may not be the case though....

 

[The Hemp Goddess]

It is the darkness that kicks the flowering hormone into gear.

 

[Locked]

Yeah AC I think you got it backwards......the long uninterrupted dark period is what builds the flowering hormone like THG said.

 

[Hushpuppy]

I agree with you Hushpuppy, as a simplified method of applying nutrients, following the light schedule to determine appropriate nutrients is easiest to implement. However, to delay a lighting switch based on nutrients as the OP stated:



is simply not necessary, and in fact (unless trying to minimize stretch), many would advise continuing to feed vegetative nutrients during the first 2 weeks of switch to ensure the plant will have sufficient nitrogen to last through flowering- particularly with long flowering sativas.

So again, I agree that it's easier for a novice, but it certainly isn't required and most likely is not the best course under good conditions, regardless of what the schedule says.

Yer absolutely right on that Just the way yu said it in the first post left me thinking it was too open ended an explanation, which could be misleading to a beginner reading it

 

[Straycat]

Hey All (Hamster, Hush, Grow, bban, et al)

Thanks for your help all. You guys are great. In the end the plants have been under HPS for almsst two days now and the nutes have been changed to transition formula using the nute chart provided by GH three part formula. I should have read up a little more on the transition to understand some of the nuances but in the end this beiing my first grow I should stick to pain vanilla.

The clones are parked under my Lavender which is almost five feet tall with a nice big cola almost four feet across so the light is not direct.. They will have a new home shortly but will remain under 24/7 light.

As soon as I get my camera fixed I will post some pics so you all can see.

This stuff is too fun.

Thx again for your help.

 

[Straycat]

I would disagree with yu BBFan on the switching of nutes. For those of us (like yerself) who really like to micro-manage our grows, we tend to "tweak" different parts of the process to maximize efficiency and yeild. For the beginner or novice grower, it would be easiest to switch nutes with the lighting switch. MJ in veg needs more Nitrogen with a little Phospherous and potassium (and other trace minerals that are with the standard nute program), but when in flower, MJ needs the nitrogen turned way down and the P and K turned up. Following the standard commercial nute schedule that comes with a given brand of nutes is the simplist way to go for beginners. Timing for this switch is not critical but is easiest to follow the light schedule, JMO.

First off, thanks again for your input. I was curious about your "tweaking" of the nutes and at first a little insulted with your implication that I might be a novice -- after all I've already been at this now for two whole months. Seriously though, thanks to you all on this website, a good mentor, several articles and videos on MJ cultivation and general hydro, aqua, soil gardening, etc.. I have a good knowledge but, as it is my first grow very little understanding, (or is it good understanding but no knowledge -- I forget the whole zen buddist comparison but it applies).

So this is a long way of saying I kind of did what you suggested with a couple adjustments only due to time constraints. I switched the nutes to the suggested nute table that comes with the General Hyrdo three part nute system at the same time of switching the lights to HPS. I did not switch to 12/12 but will do so by 9:00am tomorrow. That leaves 36hrs of nute change and 48 hr switch to HPS before going 12/12. It has to be allright this time b/c that is all I could manage. The clones remained under 24/7 light and will be moved tomorrow morning.

What I'm curious about is your thoughts on the tweakinig the nutes. I assumed that following the GH nute table takes care of the switch from N to P & K. I guess one other reason for keeping to the basics in this first grow was an unavoidable multiple strain grow. I'm kind of thinking in general if your plants are healthy any variances in nutes or the timing of transition of nutes will mostly affect the timing of flowering. In other words it will take more or less time to complete the chemical change necessary in the plants to complete flowering. With that in mind do you think flushing the plants for 24 hours or so with a nutrient salt leaching solution would help in the transition? I having been flushing every couple weeks or so anyway on the assumption my hard water (550ppm @ 0.5xEC ppm conversion) is bad for my plants. Thx again.

 

[Straycat]

everything should be just fine, as long as the light is distanced sufficiently to not burn/stress the cuttings..
BUT... 3 says of 12's might influence flowering of already mature cuttings. I jus doubt that 3 days is going to be a huge factor. Maybe those could be placed under a cfl, tube shop light, or even the window sill for an additional few hours of light p/day ??

Thx. The ebb 'n' flow system for the clone transplants is a simple one -- a cat liter box sitting on a five gallon bucket with a pump and drainage adjustments to the liter box. The whole system can be moved easily and am thinking about hooking up the one dual spectrum 400 w bulb I have provided it is not too close to the plants. I will do a test run to check the heat before I do this as currently I have no cooling fan, etc... to do a proper job. I live in a very dry, hot, hot weather climate so a window sill would be too hot for the clones. The grow room with some indirect light has been great for the clones b/c the temp is a cool 70 degrees and they seem to like this. The rest of my house is very hot and balmy as I figure I am using up my allotment of energy with the grow room. Anyhow, this is a short term solution until they find a permanent home.

 

[Straycat]

I always veg under a 24-0 light schedule...no matter if I am using HO T5's for veg or back when I vegged with HPS. I was never a fan of vegging under MH.

As for switching nutes...I use GH 3 part and provided my plants are nice and healthy going into the flip I switch to the flowering mix as soon as I flip my lights to 12-12.... If they are a lil lacking in N I do a week of a transitional mix with some extra N. Once they are in flower fully they only get two parts the rest of the way unless they get N deficient. Then I hit them off with a lil grow nutes for a feeding or two.

Jmo

Thx Hamster. I will follow this suggestion, giving them an N boost if it appears necessary. Was curious why you are no big fan of MH. This is my first grow but the MH's appeared to work well. I have heard that HPS are the more efficient lights. Anyhow, just curious. Maybe it just comes down to personal preference of which I have none yet.

 

[Straycat]

is simply not necessary, and in fact (unless trying to minimize stretch), many would advise continuing to feed vegetative nutrients during the first 2 weeks of switch to ensure the plant will have sufficient nitrogen to last through flowering- particularly with long flowering sativas.

So again, I agree that it's easier for a novice, but it certainly isn't required and most likely is not the best course under good conditions, regardless of what the schedule says.

I will definetly keep this idea in my notebook for later grows. What I am gathering from this and other posts is that as you cut back N in the flowering you still need to monitor and adjust. All my plants are Indica/Sativa mixes and flowering should not be longer than the eight to ten weeks suggested. The plants are not too stretchy yet as the inermodals (or internodes, don't know proper terminology) are pretty tightly spaced, however, I have one plant (Lavender) that is considerably bigger than the rest (4ft round x 55 in tall). Don't know if stretching will be problematic over the next two months of flowering under HPS or what to do if this occurs. I'm worried I may run out of space in the height of the room (72inches) as some inches are taken up with chain, pulley, hood, etc.. to hang the lamp. I am monitoring the temp both at base of plant and top of plant. The overall room temp is about 70 degrees but measures 75 degrees at top of lavender as is closer to the lamp. I am thinking this is ok for now. Any thoughts appreciated.

 

[BBFan]

I will definetly keep this idea in my notebook for later grows. What I am gathering from this and other posts is that as you cut back N in the flowering you still need to monitor and adjust. All my plants are Indica/Sativa mixes and flowering should not be longer than the eight to ten weeks suggested. The plants are not too stretchy yet as the inermodals (or internodes, don't know proper terminology) are pretty tightly spaced, however, I have one plant (Lavender) that is considerably bigger than the rest (4ft round x 55 in tall). Don't know if stretching will be problematic over the next two months of flowering under HPS or what to do if this occurs. I'm worried I may run out of space in the height of the room (72inches) as some inches are taken up with chain, pulley, hood, etc.. to hang the lamp. I am monitoring the temp both at base of plant and top of plant. The overall room temp is about 70 degrees but measures 75 degrees at top of lavender as is closer to the lamp. I am thinking this is ok for now. Any thoughts appreciated.

I've never used GH nutes so I can't comment on that. But yes, many folks suggest cutting nitrogen out of the feeding schedule when in flower and that leaf loss and yellowing are natural. I disagree with that thought process (along with the school of thought that recommends flushing for the last few weeks). Of course too much nitrogen can sometimes negatively affect flowering, but maintaining healthy vegetation improves harvest IMO. But 'nuff said about that.

You are heading into a major canopy issue flipping a 24/0 to 12/12 at 55" high. You will get stretch. IMO you should get some lst going on that Lavender now before you have flower set.

LST will help control your canopy. Maintaining a consistent temp between lights off and lights on is helpful in reducing stretch (most growers experience about a 10 degree swing between lights on and lights off). You only need do this for the first 2 weeks of 12/12 when the majority of stretch takes place.

Good luck and Happy Growing!

 

[Hushpuppy]

I understand what yu mean, I didn't mean to belittle yer experience. I have been seriously growing in hydro for about a year now and I still feel like a novice some days.

There is soo much to know about growing MJ, and a lot of it will come with experience, a lot of it will come from reading the experience of others. The one thing you will find from reading others' experiences is that there are a lot of viable methods and tricks that we all use, and it really depends on personal prefference as to who does what. I agree with everyone who has spoken here because all are correct for their methods of grow. There are basically 2 ways of growing MJ, one is "keep it simple" and the other is "micro-manage it".

most of us absolutely love and are addicted to growing as a hobby within itself. We just can't stay out of the garden, so we fall into the micro-manage method. There are others who like having a system that they don't have to mess with it much, they wind it up, turn it on, and watch it go. A lot of beginner or novice growers don't have the experience or are not comfortable making a lot of adjustments, so are better off "keeping it simple" until they get a few grows under their belt.

When I was talking about "tweaking", that applies to any of the small adjustments of nutrients, lighting, medium, etc... but in my last post I was talking about doing what Hammy was talking about.(adjusting the nitrogen) There are different brands of nutrients that have different methods for application. For my brand, I don't have to adjust anything for transition (with the current grow) but each strain is a little different like BBFan said (sativa dominant plants need more N for longer period going into flower than Indica dominant). If yu use a "basic nutes" program yu may find that it works fine all the way through the life cycle. But yu may also find that yu need to add some extra stuff that the "basic nutes" either don't have enough of, or their plan doesn't call for enough of it at the time that yu see yu need it. I hope I'm making sense here

When I first started, I was concerned with gettin the plants to harvest without killing them. Now I look at adjusting everything at different times and experimenting to optimize my grow and maximize my yeild. Most of us here are at that point and we try to help others not only be successful, but also maximize their yeild (as this hobby can get real expensive real quick)

It sounds like yu are doing just fine with the changes yu've made. Yu don't have to worry too much about being too precise with some things in this as MJ is relatively forgiving (and hydro will tell yu real quick if yu are doing something wrong). As yu go along yu will learn those things that are absolutes and those that are variable, and it will get easier to adjust to individual conditions.
I think flushing is a good move to use if yu have any salt or hard water issues. How often or how much is very relative to yer situation. I don't flush but twice during my whole grow. I like to flush at the change over from veg to flower to remove any buildup, and then during the last 5-8 days before harvest, again to remove any buildup that occurs from the chemical processes in hydro. I wouldn't think yu need to flush every 2-3 weeks, even for hard water, but I haven't had that problem so I can't say for sure. If yu can't get a satisfactory answer for that then try only flushing a couple times on one grow and monthly on another grow and see if yu get any problems with either of them. That will tell yu how much or even if yu need to flush in between. Probably someone here with more experience with this than me will tell yu.

 

[Straycat]

I understand what yu mean, I didn't mean to belittle yer experience. I have been seriously growing in hydro for about a year now and I still feel like a novice some days.

There is soo much to know about growing MJ, and a lot of it will come with experience, a lot of it will come from reading the experience of others. The one thing you will find from reading others' experiences is that there are a lot of viable methods and tricks that we all use, and it really depends on personal prefference as to who does what. I agree with everyone who has spoken here because all are correct for their methods of grow. There are basically 2 ways of growing MJ, one is "keep it simple" and the other is "micro-manage it".

most of us absolutely love and are addicted to growing as a hobby within itself. We just can't stay out of the garden, so we fall into the micro-manage method. There are others who like having a system that they don't have to mess with it much, they wind it up, turn it on, and watch it go. A lot of beginner or novice growers don't have the experience or are not comfortable making a lot of adjustments, so are better off "keeping it simple" until they get a few grows under their belt.

When I was talking about "tweaking", that applies to any of the small adjustments of nutrients, lighting, medium, etc... but in my last post I was talking about doing what Hammy was talking about.(adjusting the nitrogen) There are different brands of nutrients that have different methods for application. For my brand, I don't have to adjust anything for transition (with the current grow) but each strain is a little different like BBFan said (sativa dominant plants need more N for longer period going into flower than Indica dominant). If yu use a "basic nutes" program yu may find that it works fine all the way through the life cycle. But yu may also find that yu need to add some extra stuff that the "basic nutes" either don't have enough of, or their plan doesn't call for enough of it at the time that yu see yu need it. I hope I'm making sense here

When I first started, I was concerned with gettin the plants to harvest without killing them. Now I look at adjusting everything at different times and experimenting to optimize my grow and maximize my yeild. Most of us here are at that point and we try to help others not only be successful, but also maximize their yeild (as this hobby can get real expensive real quick)

It sounds like yu are doing just fine with the changes yu've made. Yu don't have to worry too much about being too precise with some things in this as MJ is relatively forgiving (and hydro will tell yu real quick if yu are doing something wrong). As yu go along yu will learn those things that are absolutes and those that are variable, and it will get easier to adjust to individual conditions.
I think flushing is a good move to use if yu have any salt or hard water issues. How often or how much is very relative to yer situation. I don't flush but twice during my whole grow. I like to flush at the change over from veg to flower to remove any buildup, and then during the last 5-8 days before harvest, again to remove any buildup that occurs from the chemical processes in hydro. I wouldn't think yu need to flush every 2-3 weeks, even for hard water, but I haven't had that problem so I can't say for sure. If yu can't get a satisfactory answer for that then try only flushing a couple times on one grow and monthly on another grow and see if yu get any problems with either of them. That will tell yu how much or even if yu need to flush in between. Probably someone here with more experience with this than me will tell yu.

Hey Hushpuppy:

Thx a bunch. Was only in jest about the novice insult. Really, more a poke at me than you thinkinig I'm experienced with only two months under my belt -- "Hey, I want to play with the big kids already."

I hear you on the addiction of growing. I don't even smoke the stuff but I love every aspect of growing it from building the room to tending the plants and you're right. It can be an expensive hobby so I appreciate all you are giving me in the advice.

I think I got your message on the flushing. I will try reducing the flushing a bit and record the changes. i was a little concerned in this first grow because some plants were having problems initially. The did recover though.

I also understand what you are saying about personal preference and personal situation. You have to read what everyone is saying, compare your situation to theirs and do your best to apply accordingly, maybe taking pieces from each method to suit your situation.

Anyhow, I think I am becoming the micro-manage type and trying to fight the temptation to constantly fiddle. Sometimes I have to just leave well enough alone.

Thx again

 

[Straycat]

I've never used GH nutes so I can't comment on that. But yes, many folks suggest cutting nitrogen out of the feeding schedule when in flower and that leaf loss and yellowing are natural. I disagree with that thought process (along with the school of thought that recommends flushing for the last few weeks). Of course too much nitrogen can sometimes negatively affect flowering, but maintaining healthy vegetation improves harvest IMO. But 'nuff said about that.

You are heading into a major canopy issue flipping a 24/0 to 12/12 at 55" high. You will get stretch. IMO you should get some lst going on that Lavender now before you have flower set.

LST will help control your canopy. Maintaining a consistent temp between lights off and lights on is helpful in reducing stretch (most growers experience about a 10 degree swing between lights on and lights off). You only need do this for the first 2 weeks of 12/12 when the majority of stretch takes place.

Good luck and Happy Growing!

Noted. I will look into this LST right away. I did make a mistake on the height of the groom room. It is actually 84'', not 72 but I don't think that makes a difference with what you are telling me.

I'll check it out. In the meantime thanks and Happy Growing? Always.