Thank you in advance for any advice, I didn't think it would be so difficult to get an answer.

I suppose one 1000 watt High Pressure Sodium (HPS) bulb with reflector might work for about 100 square feet. But, many people can't afford the cost of electricity.

Thank for your help, how much would it cost and are there any alternatives.

Find the cost per Kilowatt-Hour (kWh) on your electric bill. You will have to add a bunch of charges. For me, the cost is $0.11/kWh. That is the approximate cost per hour to run a 1000 watt bulb. If you have the bulb on 16 hrs./day, multiply that cost by 16 to find the cost per day. For me, that would be $1.76/day which would add $53 to my monthly electric bill. That's more than double for me.

There are plenty of alternatives, but my recommendation was based the theoretically best supplementation of light from a clear blue sky. If you examine this Solar Power Spectral Distribution Chart,

you can see that you probably do not need more blue light. You probably only need more red light. maybe, also far red. Those are wavelengths greater than 600 nm.

I am sorry I am so late with my thanks but I was out of town (camping). No internet .

I appreciate you breaking down the cost to run the red light versus the blue light.

Could you help me out with the "blue "light and what I would need for a 10x 10 north facing patio that is fenced in by a 6 ft fence? I have limited electronic skills but I can can garden.

THANK YOU VERY MUCH.

I think you said I needed red light not blue

Can I find what I need at a big house and garden store or at a nursery or at a specialty store?

What should I look for?

Thanks!

Hi,

So I am working under a large dome skylight but in upstate NY where clouds and shorter days tend to limit grow cycle, the dome is 13'x5' and offers all day light as we are on the second floor, in addition i have a bank of north facing windows in the room. Most of my plants are thriving without additional help; however i am trying to grow veggies in pots and recently acquired a meyer lemon loaded with immature fruit that I would like to see continue to thrive. I have added 2 26W 6400k cfl lights to the veggie grow zones.. are these overkill on the e bill? they are full spectrum, truely white, not blue.. but i just want to see more green growth and happy fruitings. the lights have definitely helped seeding development. i have hella high ceilings my ladder cannot even reach and painted brick that can be a challenge for hanging stuff on.. i saw a similar light to those i currently have but in a long 4' unit with reflector for $43, it seemed tempting but I also read a post about using chains of red and blue leds that sounded both efficient and effective.. could really use some indoor gardening advise from those experienced in this realm...

Maria, I forgot to mention that you will either have to shield the bulb and ballast from rain or buy an outdoor fixture. I really can't advise you on the best way to do that except, if possible, keep the ballast indoors. Maybe, you could shield the bulb with a window awning but not too close because of heat.

Irene, you should post your questions as a separate topic.

I like Mr Aruzinsky's answer, he is right, from the pic you can know ,when blooming ,plants dont need so many blue, they need red color, 600-660nm is right for plants.

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