5 x 5 light set up

[Prawn Connery]

But you are.

Even though it may not be a complete picture, each of the elements you are providing are a substitute for the natural environment in which the plant evolved and thrives. Your substitute may be better or worse (often worse - not you, personally, but indoor growing in general), but in each example the natural environment is your yardstick - is it not?

How much more difficult would it be to grow in a synthetic environment if we did not have the natural environment for reference?

It would be like assembling a jigsaw puzzle without a picture.

 

[ChiefRunningPhist]

I'm just going to leave this here. Its from Steve Solomon who wrote the "Intelligent Gardner." Seems this crowd would get use from this info...



Here's a clearer pic of Scully's chart ...


K is needed more than P. Not sure that's it's a 2:1 though.

Idk if you guys have heard of, or know of the KIS organics podcast (I'm kinda late to things), but I've been digging the PhD guests (episode 11 & 43) he's had on and been learning lots.

Kis Organics podcast w/ Steve Solomon...
https://www.kisorganics.com/pages/6-cannabis-cultivation-and-science-podcast

On these forums its hard to know what to trust and what not to. Who has a validated opinion? Listening to peer-reviewed experts allows me to decipher much of the info that I'm not sure about on here.

I've heard and read a lot about VPD lately, but pretty much what im finding out is that if you have high RH they drink less and if you have low RH they drink more. What I'm trying to figure out is whether the plant takes up compounds based upon their ratio in the solution or if theres singling out of one compound over another. If the plant is drinking more, is she just getting to many nutes or is she getting an unbalanced nute ratio from excess transpiration, and why and how.

 

[Frank Cannon]

Hi Grotbags and Chief, thanks for popping in! I like to read various peoples concepts to try and make a balanced opinion also, it is the internetz tho, so, so often you can be feed a load of garbage - we have been blessed on this thread that a heck of a lot has been valid through their own past experiences and thus very helpful to me personally - the usual suspects whilst often have differing opinions seem to be able to communicate like adults which is F%$king refreshing considering some of the stuff I read here on RIU and Grasscity.

Thanks for the views on nutes, I guess if I read things correctly, in no particular order:
*Be mindful of VPD, if you are getting off the scale with highish temps / lowish humidity, dilute your nutes, I should maybe check my runoff a bit more
*Nutrient make up is not the be all and end all as long as you aren't burning the buggers, salts are not building up - run off is a good thing
*Be gentle when transplanting, half strength won't hurt em for a week or so
*LISTEN, plenty of people told me I was running my nutes hard (AW16 told be a long time ago...) but alas I thought I knew better
*I probably can go to KISS easily - Coco A/B, silica, Calmag - forget about all the stuff like humic, cannazym, boost etc
*Why don't manufacturers add UV to their bloody boards, life would be easier to us LED newbs
*I've finally realised why I was an average gardener using perlite, not changing reservoir often enough and just topping up!!

Grotbag, thanks for the heads up on COGr, its not available down in the Pacific Isles so I will switch to normal ole Canna Coco instead.

Peace bruthas
FC

 

[Or_Gro]

But you are.

Even though it may not be a complete picture, each of the elements you are providing are a substitute for the natural environment in which the plant evolved and thrives. Your substitute may be better or worse (often worse - not you, personally, but indoor growing in general), but in each example the natural environment is your yardstick - is it not?

How much more difficult would it be to grow in a synthetic environment if we did not have the natural environment for reference?

It would be like assembling a jigsaw puzzle without a picture.

That’s the same argument that says, everything is organic...

Totally self-serving...

I just don’t have the time/energy to participate in a circular argument about what “nature” means....

The pieces came from nature, are selective components not complete subsystems/systems, can not self-regulate, and would cease to exist without electricity and my daily intervention...but i digress...

You confuse components sourced from nature with independent natural systems...

Feel free to rebut, i’m done on this topic...

I know you know your shit, I know a thing or too as well, I look forward to learning more from the prawn clan....

 

[Prawn Connery]

Without talking at cross purposes - because remember, you started this - all it means is I try to take my cues from nature. I don't run sterile systems. I add organics to my reservoir and beneficial bacteria and fungi to my coco. I let my pH naturally drift in my reservoir. I run my fans all the time. I start watering my plants just before the lights come on (usually when humidity in nature is highest at dawn). I don't mind a few bugs and encourage spiders and other predators to inhabit my grow room. I try not to use pesticides unless I am borderline infestation, and when I do, I use natural plant oils and other deterrents. I am in the process of trying to match my light source more closely to natural light with high CRI, fuller (more even) spectra, and emphasis on the natural flowering temperature plants might be exposed to during shorter photoperiods at latitude or near the equator, where the atmosphere is thicker and cannabis evolved (in a word, more red). I'm trying to introduce a little UV.

None of this is revolutionary. I simply control what needs to be controlled, and relinquish control of other areas where I believe they would be of natural benefit.

 

[Prawn Connery]

That’s the same argument that says, everything is organic...

Totally self-serving...

You are a little bit too cynical, my friend. But I'm also cognizant of the fact that, even though we both speak English, we don't always speak the same language.

I mean, I wouldn't go as far as saying Americans don't do subtlety, sarcasm or irony, because if you did, I wouldn't have to apologise, and if you didn't, then I'd just proved my point

 

[CanadianDank]

Hey guys, great thread you've got going here. I've been following along and there's a lot of great information being shared.
You guys have been mentioning supplementing LEDs with UV light. I grow with eb strips and sup with a powerveg in veg. What does supplementing it in flower offer? I'd love to read a bit more on this.

 

[Prawn Connery]

Hey mate, @Randomblame can certainly chime in on this, as he's been growing with UV (reptile bulbs) for a while now and has reported tangible results. I've also been experimenting with it using a CFL (cheap source of UV) and also noticed a subtle difference in end product.



There's a fair bit online if you search, but basically UV stimulates cannabinoid and terpene (essential oil) production, and not just in cannabis (terpenes, that is). Because cannabinoids break down under UV, they mostly build up in the plant during the dark period as a direct response to UV exposure during the day/lights on. This is why some growers (including myself) subject their plants to a dark period prior to harvest. This is not new, as a lot of outdoor pot farmers in the 70s and 80s also used to harvest their plants at dawn, believing they would get a better product.

The benefits of UV have also been noted by indoor growers over the years as in the early days metal halide bulbs - which produce a fair amount of UV - were used, and when indoor growers switched to HPS, they noted an increase in yield, but a decrease in quality. As a result, a lot of early indoor growers used to mix MH and HPS bulbs in the same grow, believing it was the best comprise of yield and quality. I tend to subscribe to this theory myself - though I also believe genetics plays a far bigger role in determining potency.

Some experiments have proven the UV theory, though some of the claims (THC increases of up to 30%) are perhaps best taken with a pinch of salt . . .

Nonetheless, it is real science, as it is believed cannabinoids were originally produced by the plant to protect developing seeds from damaging UV rays (cannabis sativa evolved on the equator, where UV levels are high, whereas indicas also evolved in high UV areas in the highlands of Central Asia), as well as insects and other predators.

I don't have time to go into everything now, but if you do a google search you'll find a ton of info. Hope this helps in the mean time,

 

[Prawn Connery]

Here's a spectograph of the 2700K CFL I was using. Unfortunately my spectrometer only goes down to 380nm, as CFLs also put out a bit of UVB (<320nm) as well as UVA. Fluorescent lights actually produce UV light as their base light, which is scattered by the phosphor into other spectra, producing white light. That's why UV fluorescent bulbs are clear and have no phosphor coating inside.

 

[Frank Cannon]

I think our Gangster bro also mentioned it may aid in preventing botrytis spores - thats bud rot for us dumbies - of which I never saw under HPS.
FC

 

[CanadianDank]

Hey mate, @Randomblame can certainly chime in on this, as he's been growing with UV (reptile bulbs) for a while now and has reported tangible results. I've also been experimenting with it using a CFL (cheap source of UV) and also noticed a subtle difference in end product.

View attachment 4280927

There's a fair bit online if you search, but basically UV stimulates cannabinoid and terpene (essential oil) production, and not just in cannabis (terpenes, that is). Because cannabinoids break down under UV, they mostly build up in the plant during the dark period as a direct response to UV exposure during the day/lights on. This is why some growers (including myself) subject their plants to a dark period prior to harvest. This is not new, as a lot of outdoor pot farmers in the 70s and 80s also used to harvest their plants at dawn, believing they would get a better product.

The benefits of UV have also been noted by indoor growers over the years as in the early days metal halide bulbs - which produce a fair amount of UV - were used, and when indoor growers switched to HPS, they noted an increase in yield, but a decrease in quality. As a result, a lot of early indoor growers used to mix MH and HPS bulbs in the same grow, believing it was the best comprise of yield and quality. I tend to subscribe to this theory myself - though I also believe genetics plays a far bigger role in determining potency.

Some experiments have proven the UV theory, though some of the claims (THC increases of up to 30%) are perhaps best taken with a pinch of salt . . .

Nonetheless, it is real science, as it is believed cannabinoids were originally produced by the plant to protect developing seeds from damaging UV rays (cannabis sativa evolved on the equator, where UV levels are high, whereas indicas also evolved in high UV areas in the highlands of Central Asia), as well as insects and other predators.

I don't have time to go into everything now, but if you do a google search you'll find a ton of info. Hope this helps in the mean time,

Thanks for the great response. I'd heard a lot of that before but I did not know UV stimulated terpene production.
I'll do some searching around for more info, but this is all starting to make more sense to me. Especially when you brought up growers noticing that difference when switching to hps from mh. Explains why I've been so interested in CMH lights and the wonderful herb they produce. I ended up going the LED route but I still want one one day.

 

[Prawn Connery]

I think our Gangster bro also mentioned it may aid in preventing botrytis spores - thats bud rot for us dumbies - of which I never saw under HPS.
FC

Mate, if you've never had bud rot problems before, then you've probably just been lucky. HPS does emit some UV, but not a huge amount. When you hold a HPS bulb up to the light, you may notice a slightly green tinge to the glass tube surrounding the element. This is iron content in the glass that is used to block UV rays. So even though HPS elements produce UV radiation, much of it is blocked by the glass tube. But still, it emits more UV than LED. In fact, even white phosphor LEDs emit some UV radiation, though it is a very, very small amount.

Onto the subject of mold, or bud rot.

The reason you've been lucky not to get it in the past may come down to three things:

Strain - some strains are more resistant to mold than others, which usually comes down to bud structure. Tight buds allow humidity to build up in between the calyxes and leaves, as they offer little air circulation, which can result in mold if spores get in. However, some strains have super-tight buds that, although they produce high humidity, also prevent mold spores from entering. Without mold spores, there will be no mold. At the other end of the scale, airy buds are obviously more mold resistant. Sativas tend to be much more mold resistant than indicas. This is mostly to do with bud structure. I have a theory that sativas developed skinny leaves and airy buds for this evolutionary reason - to prevent mold in high humidity conditions in the tropics. Indicas, on the other hand, evolved in drier regions.

Air flow - even though you weren't running fans, you may have had sufficient air flow anyway through your grow room that prevented humidity building up in your canopy. Your canopy may also have been "loose" enough to permit adequate airflow around it: by "loose", I mean perhaps your plants weren't as tightly packed together, or perhaps your bud development wasn't optimal, or just average, and that prevented your buds getting to a size where humidity built up deep inside, leading to mold.

Ambient conditions vs grow style - You live in a dry place, generally with low ambient humidity, but some forms of hydroponics are more conducive to humidity than others. Closed systems - such as DWC buckets, or NFT channels with remote reservoirs etc - do not allow much nutrient solution to evaporate into the atmosphere (grow room), where as a switch to coco pots - which are open and always moist - does allow humidity to build up through evaporation. On the subject of VPD, you'll probably find the vapor pressure difference in your flowering room is a lot less than in your veg chamber because there is a lot more evaporation going on in your flowering room due to all that moist coco, as well as vegetation transpiring.

You asked earlier about getting rid of mold spores to prevent mold. Unfortunately, you can never get rid of them completely - they are always in the air - though obviously once you get mold, it will release a lot more spores in the vicinity and increase the concentration (and likelihood of spreading to other areas).

So mold prevention is much easier than cure.

 

[Rocket Soul]

Mate, if you've never had bud rot problems before, then you've probably just been lucky. HPS does emit some UV, but not a huge amount. When you hold a HPS bulb up to the light, you may notice a slightly green tinge to the glass tube surrounding the element. This is iron content in the glass that is used to block UV rays. So even though HPS elements produce UV radiation, much of it is blocked by the glass tube. But still, it emits more UV than LED. In fact, even white phosphor LEDs emit some UV radiation, though it is a very, very small amount.

Onto the subject of mold, or bud rot.

The reason you've been lucky not to get it in the past may come down to three things:

Strain - some strains are more resistant to mold than others, which usually comes down to bud structure. Tight buds allow humidity to build up in between the calyxes and leaves, as they offer little air circulation, which can result in mold if spores get in. However, some strains have super-tight buds that, although they produce high humidity, also prevent mold spores from entering. Without mold spores, there will be no mold. At the other end of the scale, airy buds are obviously more mold resistant. Sativas tend to be much more mold resistant than indicas. This is mostly to do with bud structure. I have a theory that sativas developed skinny leaves and airy buds for this evolutionary reason - to prevent mold in high humidity conditions in the tropics. Indicas, on the other hand, evolved in drier regions.

Air flow - even though you weren't running fans, you may have had sufficient air flow anyway through your grow room that prevented humidity building up in your canopy. Your canopy may also have been "loose" enough to permit adequate airflow around it: by "loose", I mean perhaps your plants weren't as tightly packed together, or perhaps your bud development wasn't optimal, or just average, and that prevented your buds getting to a size where humidity built up deep inside, leading to mold.

Ambient conditions vs grow style - You live in a dry place, generally with low ambient humidity, but some forms of hydroponics are more conducive to humidity than others. Closed systems - such as DWC buckets, or NFT channels with remote reservoirs etc - do not allow much nutrient solution to evaporate into the atmosphere (grow room), where as a switch to coco pots - which are open and always moist - does allow humidity to build up through evaporation. On the subject of VPD, you'll probably find the vapor pressure difference in your flowering room is a lot less than in your veg chamber because there is a lot more evaporation going on in your flowering room due to all that moist coco, as well as vegetation transpiring.

You asked earlier about getting rid of mold spores to prevent mold. Unfortunately, you can never get rid of them completely - they are always in the air - though obviously once you get mold, it will release a lot more spores in the vicinity and increase the concentration (and likelihood of spreading to other areas).

So mold prevention is much easier than cure.

Mold spores: one way of minimising mold spores in your grow room is to run positive pressure instead of negative with HEPA filter on your intake. The positive pressure makes sure your space doesnt suck in any air from outside thru cracks and such. Ive heard its also is easier to maintain high RH blowing instead of sucking (yeah theres a joke there )
Harder control smell though.

 

[Prawn Connery]

Yeah, smell is usually the problem with positive pressure grow rooms, as it's really hard to seal everything off.

 

[Randomblame]

Hey guys, great thread you've got going here. I've been following along and there's a lot of great information being shared.
You guys have been mentioning supplementing LEDs with UV light. I grow with eb strips and sup with a powerveg in veg. What does supplementing it in flower offer? I'd love to read a bit more on this.

The Agromax Powerveg bulbs have exactly the same spectrum like a 10-12% reptile bulb(see below and on the powerveg website). This means in the flowering stage you would see a good effect with ~12-14" distance to the canopy(150-200μW/cm²}. But because these bulbs have very little output below 295nm I would recommend to use them 4-12h per day. You could start with 2+2h(beginning and end of the day) and increase slowly to 8-12h per day. T5 reptile aka Powerveg bulbs have no damaging effect like the 5 times stronger PureUV bulbs. These bulbs go below 275nm which is already UVC! 10nm in this area means the photons carry 10 times more energy and the gap between these two types of bulbs is almost 20nm.
You could exchange the Powerveg and replace it with a PureUV but these bulbs can only be used for 1-2h the day and you need a minimum distance of 20-24" to avoid issues with heatstress and wilting fan leaves. I've used it just two days with 16" distance and 2h and 4 of 5 gals have lost most of the upper fan leaves.
So in the end it depends on your prefered hanging heights in the flowering stage which type of bulb fits better in your system.
The PureUV saves for sure energy and last much longer but you maybe need some kind of UV filter in front of the bulbs to halve the intensity. I have DIY spreaders to reduce center intensity and throw some of the light back into the reflector but you can also tighten a curtain over the reflector. Depending on material and mesh width it should reduce UVB intensity by 25-50%. The "reptilians" use such curtains when they change the old bulbs because in the 1st 100h new bulbs can output much more UVB.

I would at first try it with the powerveg bulbs and run them all day long when you see the first trichomes are forming. That's the best moment to increase the treatments cuz from this point on the plants are fully focussed in protecting the flowers and seeds.

If you compare this 12% UVB spectrum and the Powerveg spectrum you'll see it's pretty much the same and you can use them in the same way reptile bulbs are used(6-12h). Powerveg and PureUV anyway use the same sockets and ballast so you can also change them later when you have more experience with UVB.

 

[CanadianDank]

The Agromax Powerveg bulbs have exactly the same spectrum like a 10-12% reptile bulb(see below and on the powerveg website). This means in the flowering stage you would see a good effect with ~12-14" distance to the canopy(150-200μW/cm²}. But because these bulbs have very little output below 295nm I would recommend to use them 4-12h per day. You could start with 2+2h(beginning and end of the day) and increase slowly to 8-12h per day. T5 reptile aka Powerveg bulbs have no damaging effect like the 5 times stronger PureUV bulbs. These bulbs go below 275nm which is already UVC! 10nm in this area means the photons carry 10 times more energy and the gap between these two types of bulbs is almost 20nm.
You could exchange the Powerveg and replace it with a PureUV but these bulbs can only be used for 1-2h the day and you need a minimum distance of 20-24" to avoid issues with heatstress and wilting fan leaves. I've used it just two days with 16" distance and 2h and 4 of 5 gals have lost most of the upper fan leaves.
So in the end it depends on your prefered hanging heights in the flowering stage which type of bulb fits better in your system.
The PureUV saves for sure energy and last much longer but you maybe need some kind of UV filter in front of the bulbs to halve the intensity. I have DIY spreaders to reduce center intensity and throw some of the light back into the reflector but you can also tighten a curtain over the reflector. Depending on material and mesh width it should reduce UVB intensity by 25-50%. The "reptilians" use such curtains when they change the old bulbs because in the 1st 100h new bulbs can output much more UVB.

I would at first try it with the powerveg bulbs and run them all day long when you see the first trichomes are forming. That's the best moment to increase the treatments cuz from this point on the plants are fully focussed in protecting the flowers and seeds.

If you compare this 12% UVB spectrum and the Powerveg spectrum you'll see it's pretty much the same and you can use them in the same way reptile bulbs are used(6-12h). Powerveg and PureUV anyway use the same sockets and ballast so you can also change them later when you have more experience with UVB.

View attachment 4281998

Thank you so much for your awesome response Randomblame. You just answered every question I had! I'm definitely going to throw it in the tent soon. In doing an LED only comp right now so it will have to wait unfortunately, but I am excited to try this out next time!
I had been holding off because I was not sure how much and what distance was safe, I was worried it would harm the plant or degrade the thc.
Thanks again!

 

[Randomblame]

Thank you so much for your awesome response Randomblame. You just answered every question I had! I'm definitely going to throw it in the tent soon. In doing an LED only comp right now so it will have to wait unfortunately, but I am excited to try this out next time!
I had been holding off because I was not sure how much and what distance was safe, I was worried it would harm the plant or degrade the thc.
Thanks again!

Nope, no worry there is no degradation! But the plants will stay a bit shorter and more compact cuz when the UVR8 molecule is triggered the plant switch in a kind of protection mode and in this mode you'll get less stretch. The plant fully concentrate in protecting the next seed generation from getting damaged even if there is not a single seed. T
HC is a perfect UV filter and factor 50 sunscreens for instance use molecules of similar composition to protect the skin.

Each strain reacts a little different to UVB. Some can handle more like others which is espechially important with the PureUV bulbs. The Powerveg aka reptile bulbs don't have such problems because the spectrum and intensity is much more natural.
Below is a test of a 2ft Arcadia bulb with 12% UVB and 30% UVA and when you scroll down there is a spectrum chart. You can see these bulbs have almost the same UVA to UVB ratio like the sun and indeed reptile bulb manufacturer are trying to mimic the sun. The PureUV spectrum has 75% UVB and only 25% UVA so its completely the opposite ratio and there is also a small amount of UVC. But even in 5000m above zero there is no measurable radiation below 280nm and UVC is a destroyer. Within seconds it kills insects and spores and its really important to protect your eyes and skin when you visit you groom.
These two main differences makes it much more difficult to work with this type of bulbs. I've already ordered a dimmable T5 ballast to have more control of the UVB intensity and being able to use them with less than 24" distance.
My prefered hanging height of the light is ~12-14" where I get ~800-900μMol/s/m² but its impossible to use them at this height and at 24" I've only 600-700μMol/s.
All this makes the reptile bulbs much better for beginners. They need more time and energy but in the end the effect is pretty much the same. Both types of bulbs can increase thc content by up to 30% and more. A 10% strain can finish with 13 or even more percent thc that's true. But I don't thing you can get 30% out of a 24% strain like gg#4.
How much it is is always strain dependent. More UVB means more thc but only up to a certain point. As soon as you damage the plants you'll lose yield.
I've burned my gals their asses off around week 7 and 2 of them stopped growing completely. They've developed an impressive dense trichome layer and quality is for sure top notch but this round (the 1st with the PureUV bulbs) I've lost for sure up to 20% in yield.

 

[PSUAGRO.]

The pureuv bulb is scary........turn your plastics into crispy,crispy

 

[Moflow]

The pureuv bulb is scary........turn your plastics into crispy,crispy

And my skin!

 

[Fake stoker]

Definitely move to LED. Also, if you've been running HPS, I'm sure that heat from LEDs will not be a problem. But for a 5X5, I'd definitely say to do it "right", shoot for 8-900 watts.

This is totally true