Building a Cree Light for a 2x2 area. ( suggestions, thoughts, etc. )

Rahz said:

Some lighting strategy might improve the returns, not to negate what you're saying.

Good:
plant 1, 8 weeks 800 PPFD

Better(?):
plant 2, 3 weeks 500 PPFD, 4 weeks 900 PPFD, 1 week 500 PPFD. Average PPFD over time: 700

Best(?)
plant 3, 3 weeks 550 PPFD, 4 weeks 1050 PPFD, 1 week 550 PPFD. Average PPFD over time: 800

Click to expand...

You really think you should dim the last week of flowering?

If the last week is more about ripening than adding bulk, maybe. It just depends on whether moving that energy back into the previous 3 weeks is better than leaving it on the end. I don't have any objective data to back it up but it seems logical.

Rahz said:

Some lighting strategy might improve the returns, not to negate what you're saying.

Good:
plant 1, 8 weeks 800 PPFD

Better(?):
plant 2, 3 weeks 500 PPFD, 4 weeks 900 PPFD, 1 week 500 PPFD. Average PPFD over time: 700

Best(?)
plant 3, 3 weeks 550 PPFD, 4 weeks 1050 PPFD, 1 week 550 PPFD. Average PPFD over time: 800

Click to expand...

Oh yeah turn down first bit then increase and end......

On my current run I am trying a new experiment

For this run I am dimming the first and last hour of lights on during 12/12

So my lights on is 8am-8pm. From 8am to 9am it's in veg mode, then from 9am to 7pm it's on full blast. From 7pm to 8pm it goes back down to veg.

The reasoning, to better replicate an outdoor environment. Throughout the day from sunrise to sunset, light intensity is variable. It's never a fixed value, especially during the morning and evening hours when the sun's intensity is much lower.

I've read specifically in the morning hours that plants go through a "wake up" period when the sun begins to rise, and for indoors, reducing the amount of light plants receive when the lights first kick on can greatly reduce stretch and promote tighter node spacing.

I'm theorizing that the same reduction in intensity before lights out can help increase the rate of ripening and improve overall resin production.

I need to learn how to fuck with arduinos and buy one.

Doing some testing tonight without fans on to cool heatsinks.

Lights at around 1.3 A and an hour or so later temps in the tent are 82F and the LED temps are 45-55C not bad for just passive. Room temps 74-75F with small ac running. I will keep testing and see if anything changes.

Uberknot said:

Doing some testing tonight without fans on to cool heatsinks.

Lights at around 1.3 A and an hour or so later temps in the tent are 82F and the LED temps are 45-55C not bad for just passive. Room temps 74-75F with small ac running. I will keep testing and see if anything changes.

Click to expand...

Not bad.... tested for a few hours more and the LED's are 50 - 55C without the fans running and tent temps staying 82F

Turned on the fans last night to test the difference with them running and the LED temps drop to 35-40C with the tent still at 82F.

Uberknot said:

Not bad.... tested for a few hours more and the LED's are 50 - 55C without the fans running and tent temps staying 82F

Turned on the fans last night to test the difference with them running and the LED temps drop to 35-40C with the tent still at 82F.

Click to expand...

You're in good shape then! But remember, the cooler the cob, the more lumens!!!

Ok we have test results!!

Hey There,

Had a little fun today with my sons tablet and measured the Lux of the light in the center of the tent right above the plants. at about 24".

With them turned all the way down at 875 mA the reading was approx 38,000 Lux.
With them turned all the way up at 1750 mA the reading was approx 77,000 Lux.

Converted to Lumens...roughly?

875 mA ~ 25,000 lumens
1750 mA ~ 50,000 lumens
The lights were just turned on.

So a rough basic test but a test none to less I will have to test them another time after they have ran for awhile.