Window Full Sun vs 1,000w. HPS

I have a 1kw HPS, but I also have a pretty big window on the sunny side. This isn't your normal everyday window, it's a thin single pane glass in a trailer. It isn't 3 layers full of Argon and other sun ray blocking things.

I was wondering if when the sun came out on a cloudless day, wether it would be good to get the plants into the sunlight, and save some electricity for those few hours.

Also, is there a significant drop in sunlight intensity during the winter, that might make placing plants in the sun less effective than in summer?

You'll be better off keeping them under your HPS during the winter. This chart shows how much less light output we get in the US over the course of winter and the year in general.

http://www.extension.purdue.edu/extmedia/HO/HO-238-W.pdf

Thanks for the link.

Has anybody got one of those expensive light meters? Some real #s are always welcome.

The real sun on a cloudy day beats a hid light anytime imo. Your window southern exposure or is it indirect light?

Sun comes right in. During Summer, I was running a 400w. HPS. I can tell the sun beats that light just by the growth difference in weeks that I could use the direct sun. I could get about 5-6 hours in summer, not sure about winter yet.

That 1,000w makes the 400 look dim though lol, so I wasnt sure if putting them in even the best of Michigan winter sunlight was worth the time. I'm usually home during the day, so putting the plants in the sunbeam isn't an issue for me.

I just checked, FWIW:

14" under my 600W MH I get 2600 candlepower, light coming through a south facing sliding door, double paned, on a partly cloudy day I get 3700 CP, outside of door (no glass) was 5100. I think I've checked outside on a summer day and it gets up around 7000.

I like to move plants into the sun when possible. The sun certainly seems brighter, but I've always wondered what part of the spectrum I might be filtering out when it goes through a window.

SnapsProvolone said:

The real sun on a cloudy day beats a hid light anytime imo. Your window southern exposure or is it indirect light?

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I disagree. In this post Tags clearly shows that on a cloudy day the umol reading was only 99 while during a sunny day it was 1300+ in the same location. Meters don't lie. Sure you do however still get UV light and infrared from that sun that passes through clouds better but those wavelengths are not known for producing either types of chlorophyl. https://www.rollitup.org/led-other-lighting/676858-tags-high-efficiency-lighting-garden-45.html#post9763216

I did read somewhere that UV and UVB rays help to develop the THC however as the plant is growing the trichs. I guess you need reptile bulbs to reproduce that indoors.

ProdigalSun said:

I did read somewhere that UV and UVB rays help to develop the THC however as the plant is growing the trichs. I guess you need reptile bulbs to reproduce that indoors.

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Yeah I've read that too. I got them for my current grow will have to find out after harvest if the increase is noticeable.