Need help of peeps smarter than me..

[megayields]

I am going to move my op into a 24K square foot greenhouse and we are putting 100 - 50 gallon smart bags in their for an early crop. I need supplemental lighting, I've seen others do it with CFL (T-5's) we believe the 100 bags will take up about 3,000 sq ft...

MY QUESTION - Is their a way for me to calculate how many T5's I need to just supplement 4 hours of darkness (2 in the morning...2 in the evening) until late March?

Thank you

 

[BrownThumb]

Do I understand correctly if I say 3000' divided by whatever you consider to be supplemental lighting psf? What do you consider to be "supplemental" wattage psf? Just curious, it's an interesting question.

 

[longwaters]

http://aesop.rutgers.edu/~horteng/ppt/papers/SUPPLIGHTINGPAPER.PDF

 

[wildgrow]

Considering their limited penetration, I think ideally you would want them running continuously along the length of your overhead trusses.

Do you care if its just enough light to break the dark or do you want to get growth out of them? I would think the 1st, as the 2nd would be costly.

I use a 100 w cfl for 2 hours of 'sunrise' and 2 of 'sunset' in my closet.

I dont know if Im smarter than you, but I am smarter than a 5th grader.

 

[SeaMaiden]

I have no idea, but I'm tagging along for my own education should an answer (just opened up the pdf longwaters posted) be put forth.

 

[Granger2]

Megayields,
Are you trying to run enough light to make them grow, or just to manipulate day length/bloom? It takes WAY less to merely extend day length. I can't tell you how many watts etc. Depends on many factors, but on my much smaller scale, I use one 13w CFL for one hour in the middle of dark period/"night" in a 3x3' stall to keep plants in veg.

If you are only trying to keep them in veg, you don't need to extend the day length. All you have to do is to interrupt the plants night period with light for one hour, probably less. Good luck. -granger

 

[SeaMaiden]

Granger, IME with cannabis you should use at least 1hr, I use 2, twice during the dark phase.

 

[Hydro-Soil]

You'll want to put a 600-1000w hps about every 10x10.

You'll get better penetration, have to buy fewer lights and run a lower power bill. Plus they're warmer for spring temps.

Stay Safe!