Switch from 18-6 to 12-12 to finish Autos?

Masterdank420

Well-Known Member

Masterdank420

Well-Known Member
I live in Interior Alaska and I've never had an auto finish outdoors. Last year I got the closest but no banana. Autos suck.

I don't have photos finish either but they do get big.
Im almost in the same boat, last frost at end of may to start of june and first frost September. It's hard to get to the end with something that isn't rotten or frost burned lol. This year i hauled em inside to finish cause it wouldn't stop raining and temps dropped to 10 degrees at night only went up to 14 in the day.
 

twentyeight.threefive

Well-Known Member

Masterdank420

Well-Known Member
I grow my autoflowers on 18/6. As long as you aren't exceeding the maximum DLI for the plant you can run 24/0.

Higher power lights (PPFD) can hit the maximum DLI in less time allowing you to run shorter daylight schedules.
Ive got 900w of high intensity led going lmao how do i figure out the numbers?
 

LeastExpectedGrower

Well-Known Member
I'm running 18/6 with autos. Before I had sufficient lighting I was doing 20/4, but I subscribe to the school of paying attention to DLI. I'm probably running a bit 'hotter' on that than I need to, somewhere in the 45-50DLI range in flower, but it's in my nature. The plants don't seem to mind. My tent is only about 14 square feet and I'm running 675w of HLG units (but dimmed down a bit).

For all the 'plants may get 24 hours of light' in a place that very few of us will ever grow; I don't think you want to reduce the equation to JUST number of hours. Sure there may be 'not darkness' in some seasons for places like Siberia but that doesn't mean that for a number of hours there's the substantial PPFD that really count for much.
 

twentyeight.threefive

Well-Known Member
I got 3 mars hydro tsl 2000 all hooked up covering an area 4x4. They pull 300w from the wall each.
Seems like one too many lights, at least for veg.
The Mars Hydro TSL 2000 has a maximum PPFD of 997 µmol/m² and an average PPFD of 727 µmol/m².

Maximum DLI will vary from strain to strain and even phenotypes.

From what I've read veg DLI around 20-35 and flower about 40-65.

If you assume an average of 727 µmol/m² across your grow you should run your lights at 70% to achieve 33 DLI.

In flower 727 µmol/m² will give you about 31.5 DLI over 12 hrs.


There are a lot of variables, but knowing your actual PPFD values would be required for true numbers.

DLI Calculator
 

Masterdank420

Well-Known Member
Seems like one too many lights, at least for veg.
The Mars Hydro TSL 2000 has a maximum PPFD of 997 µmol/m² and an average PPFD of 727 µmol/m².

Maximum DLI will vary from strain to strain and even phenotypes.

From what I've read veg DLI around 20-35 and flower about 40-65.

If you assume an average of 727 µmol/m² across your grow you should run your lights at 70% to achieve 33 DLI.

In flower 727 µmol/m² will give you about 31.5 DLI over 12 hrs.


There are a lot of variables, but knowing your actual PPFD values would be required for true numbers.

DLI Calculator
Thanks man, I dont use those lights in veg, too potent lmao. I use crappy cheap wish.com "10,000watt light For that lmao .I'll get my buddy over with his fancy gadgets for measuring light and ill figure it out from there lol.:dunce:
 

LeastExpectedGrower

Well-Known Member
Now that is something that I needed to know! I'll go to 18-6 in my big light tent from here on out.
You can play around with the numbers a bit...Last cycle I ran 17/7 schedule without a problem, and you could probably even do a 16/8 and have it work...just a matter of figuring out what your PPFD is and calculating the DLI and making sure you're providing that DLI across a day.
 
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