Yet another UV thread

nachooo

Well-Known Member
Been reducing lights on time for quicker flowering. So long as we provide them enough during lights on, they benefit from the extra dark time. All about the DLI!
Exactly, Is incredible how well it work, I am 2 weeks into flowering sativas with far reds (five minutes after day time) at 10/14 (16) and flowering is right now like 3 weeks with clasical 12/12....I expected less diference to be honest...I have kept similar DLI and think plants are less stressed at the end of the day... Its a quick sativa that usually takes aprox 9 weeks.. for sure they will be ready in 7 total weeks or less.. I have some quick indica genetics that usually are ready in 6-7 weeks....I have to try same reduction in flowering time...4-5 weeks total....hope that it works like with the sativa..
 

canadian1969

Well-Known Member
they benefit from the extra dark time
If we assume 25 moles/s/m2 as the DLI and I am pushing say 700 umoles PPFD, thats 0.0007 moles/s/m2 multiplied by 60 for 0.042 , multiplied again by 60 to the hourly rate 2.52 moles
Take the 25 mole saturation point divided by 2.52 moles/hour = 10 hours. Saturation at 10 hours means they could be off for 14 hours. So in theory you only need low wattage maintenance light to maintain whatever light cycle you want? I thought the idea was to extend the lights "on" part to 14 hours and lights "off" for 10 to get to harvest quicker. No?


I took some readings with my LUX meter as I do not have a PAR meter (yet),
Canopy Height 24" (as an initial test height, scrog screen height)
Light Measurements (Lux dimmed/full) @ canopy
5700K 1400/36000 Lux
3000K 2000/31000 Lux
DualK 3400/67000 Lux
Power Range
5700K 14.2-229 watts
3000K 17.7-216 watts
Total full power with fans 460 watts (not intended to run at this level)
I am running about 50% power for efficiency (so dimmed to about 700ma on the EB strips)
So I figure I get around 40,000 Lux at about 240 watts. I have enough head room that I can shift the spectrum and still maintain operational power.
Any rough ideas about where this would be with a PAR meter?
The tent is approx 0.5 m2
 
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Photon Flinger

Well-Known Member
1 DLI is 278 PPFD over one hour. 2 DLI is 550, 3 DLI is 825, etc. You might find it it easier to use.

If your target DLI is 24-36 for example you could get that with 8-12hr @825 PPFD or 12-18hrs @550 PPFD.

I go the other way and deliver 1500-1850 PPFD to the canopy and have dropped my lights on to 5.5hrs for roughly 33 DLI.

That much in a small tent will give you a lot. On full my guess would be 2500+ at 8", around 1500-2k at 12"
 

canadian1969

Well-Known Member
Working through some of the power supply requirements. Thoughts or suggestions anyone?
All eBay drivers
http://www.ebay.ca/itm/122480543106

280nm 4x parallel 6.5v 200ma
6W 1-2X2(3)W 600mA 2-6.8V

360nm 10x series 3.5-4v 700ma
30W 10-18X2(3)W 600mA 30-60V

660/730's 10 x series 2-2.4v 700ma (each, same type power supply)
20W 6-10X2(3)W 600mA 18-35V

Next I have to figure out how to put them on separate timers. Suggestions are welcome. I guess doing it ont he AC side makes the most sense, so a 110v AC digital timer with min 4 outputs I suppose.
 
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KonopCh

Well-Known Member
1 DLI is 278 PPFD over one hour. 2 DLI is 550, 3 DLI is 825, etc. You might find it it easier to use.

If your target DLI is 24-36 for example you could get that with 8-12hr @825 PPFD or 12-18hrs @550 PPFD.

I go the other way and deliver 1500-1850 PPFD to the canopy and have dropped my lights on to 5.5hrs for roughly 33 DLI.

That much in a small tent will give you a lot. On full my guess would be 2500+ at 8", around 1500-2k at 12"
So you saying that 19h off, 5h on will deliver same yield as 12h off, 12h on? I should try this...
 

Photon Flinger

Well-Known Member
So you saying that 19h off, 5h on will deliver same yield as 12h off, 12h on? I should try this...
It did work for me with those numbers on a sativa during my 80 vs 90 CRI comparison. At 12/12 they were flowering but not finishing so I started to drop it. Last 3 weeks were 5.5hrs on and yield looks to be in range, still drying and curing. Going to try with an indica/hybrid next run 5.5 lights on from a 12/12 veg cycle.

I think 36 DLI is a good starting point. You can go up or down from there to find out what your plant likes best. Then increase the intensity (lower lights, more power, etc) and reduce the light hours while maintaining the same DLI. The more dark you can get them the more flowering hormones the plant will produce.

Give it a try yourself, grab a PAR meter and a calculator!
 

nachooo

Well-Known Member
It did work for me with those numbers on a sativa during my 80 vs 90 CRI comparison. At 12/12 they were flowering but not finishing so I started to drop it. Last 3 weeks were 5.5hrs on and yield looks to be in range, still drying and curing. Going to try with an indica/hybrid next run 5.5 lights on from a 12/12 veg cycle.

I think 36 DLI is a good starting point. You can go up or down from there to find out what your plant likes best. Then increase the intensity (lower lights, more power, etc) and reduce the light hours while maintaining the same DLI. The more dark you can get them the more flowering hormones the plant will produce.

Give it a try yourself, grab a PAR meter and a calculator!
I have seen happier plants at 10/14 (16 far red) than in 12/12...And also some stretch reduction, I am now at 1200 ppfd aprox..with side lighting .in a 0,64 square meter wich is a 7-8 square foots...as I have 28 celsius in canopy I could not resist to add some guetto C02, so I add 3 bottles of gelatine sugared with yeast, I still vent slowly, but exhaustion is slow at the top of tent so in a manner I will be increasing CO2..Plants are all praying more than usual ..since I add it.. Attach a video of my CO2 guetto generator...the rate of bubbles has been constant in all bottles for 4 days until now thanks to the gelatin..and seems that is a good rithm...IMG_20170922_195236.jpg
 

Photon Flinger

Well-Known Member
You can also use crushed eggshells mixed with vinegar as a natural CO2 generator. Once done after a few days it makes for a great way to boost calcium.

Not a fan of excessive CO2 supplementation since you can accomplish the same by increasing airflow through the grow area.
 

nachooo

Well-Known Member
Well..is just a little CO2 more in the recipe..it cost me less than 10 dollars and less than 2 hours to build it in my free time and I enjoy a lot this litlle proyects :) By the way..vinegar smell terrible for that...much worst than yeasts.....Just pushing the tent to the limit...last time I got 375 gr aprox... in 0,64 square meters.....trying to reach 400 or more reducing flowering time...
 

Photon Flinger

Well-Known Member
Well..is just a little CO2 more in the recipe..it cost me less than 10 dollars and less than 2 hours to build it in my free time and I enjoy a lot this litlle proyects :) By the way..vinegar smell terrible for that...much worst than yeasts.....Just pushing the tent to the limit...last time I got 375 gr aprox... in 0,64 square meters.....trying to reach 400 or more reducing flowering time...
Agreed it does stink. Helps keep bugs at bay :)
 

Photon Flinger

Well-Known Member
you are such an idiot. tell me just what is that magical flowering hormone ? there is no such thing. don't even start with hypothetical florigen

Oh really then why are we manipulating the photo-period to induce flowering?

Anyhow, no doubt you will reply so before that keep drinking the koolaid you guys are making for the gg and friends comedy grow.
 

Photon Flinger

Well-Known Member
phytochrome reaction is well established BUT it is not a flowering hormone.

It affects hormone production.

Rather than banter back and forth, I will clarify the statement as longer dark periods result in better flowering. Is that fair?

Simple and can be tested by anyone.
 

PurpleBuz

Well-Known Member
It affects hormone production.

Rather than banter back and forth, I will clarify the statement as longer dark periods result in better flowering. Is that fair?

Simple and can be tested by anyone.
plant physiologists and biochemists have tried for centuries to find that magical florigen and it has never been found.

and yes the simplified statement is A OK up to a point there isn't much difference between 14 hour dark and 16 hour dark
 

nachooo

Well-Known Member
and just what are "auxins" are you talking about ?

IAA ? IBA ? what oh btw neither IAA or IBA stimulate flowering.......
Is a very complex process that is not yet clear totally...I do not try to figure it..I let it to science guys. And hormones play a big role in it...is not as simple as add some hormones and wait for the flowers..lot of more things involved
 

Photon Flinger

Well-Known Member
Is a very complex process that is not yet clear totally...I do not try to figure it..I let it to science guys. And hormones play a big role in it...is not as simple as add some hormones and wait for the flowers..lot of more things involved
Hormones rather than hormone. Huge difference.

We aren't saying that you can replace the dark period with a magic hormone as he put it. We are saying that a longer dark period can produce better results in flowering.
 
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