how does overcast relate to full on sun?

are the lumens drastically lowered? i have 8 23w cfls in my closet, and its overcast outside. i usually throw the girls outside during the day, but idk if my cfls or outside is better

anyone got any reading on the subject?

thanks!

Shade still counts as daylight.

Good question, I've been wondering the same thing. Even with moderate overcast, it still seem pretty bright outside.

If I remember correctly the plant thrives on the UV spectrum of light... so even on over cast days the UV index is still up hence the growth. I will have to check on the facts just to be sure but I am 90% positive that's how it works.

Cheers,
BR.

how much direct sunlight should a plant get

That would all depend on what stage your plant is in... the amount of light will vary... but assuming it's an outdoor grow you would want as much as possible in my opinion a minimum of at least 5 hours. Everything I have read and seen indicates the more direct sun light your plant gets the better it will grow and produce. I am sure there are others on here that will chime in on the subject of what is optimal for plant growth.

Cheers,
BR.

hmm thanks for the replies

ill bet if someone put a light meter outside we could find out the truth

I'd also like to know how direct sun affects our babies in the flowering stage. Its been hot as balls here for a while and I'm losing some fan leaves to the heat. I'm growing on a deck with curtains. should I keep the curtains closed during the day as well, its still pretty light, like I said, I been flowering for about 3 weeks.

It's best to use sunlight because your covering a broader light spectrum than you can with ANY indoor lighting. The plant will build more resins in the flowering stage to protect itself from those lights. Like Blackrain said, the UV rays are still high. That's how alot of people get sunburn on cloudy days, they never think about the other rays that make it through. Sunlight will always be the best if you can.

Dam right, nothing beats the sun!

Luger187 said:

hmm thanks for the replies

ill bet if someone put a light meter outside we could find out the truth

Click to expand...

I measure 4000 ft candles, overcast middle of day. utilizing the popular hydrofarm meter. This is the reading i would expect from say a 400 watter @ 18" or so.
So even though it's cloudy, its still very productive.

patlpp said:

I measure 4000 ft candles, overcast middle of day. utilizing the popular hydrofarm meter. This is the reading i would expect from say a 400 watter @ 18" or so.
So even though it's cloudy, its still very productive.

Click to expand...

good info! thanks man +rep

bump
anyone got more info?

Yes, my photochromic specs still go dark on very overcast days - it´s the UV that does that.

thanks spanishfly