how long should i keep the light on

18 hours of light and 6 dark per day during the veg stage. 12/12 for flowering
Have ayou checked out anyone's else's grow journal. Or the Mj Bible at Garden'sCure.com?

 

is your bulb an incandescent or flourescent bulb?

 

Light Bulb Comparison:

 

^ if those cost savings aren't obvious to anyone, let me know and I'll come over and hit you on the head with a tack hammer.

 

Wait a minute!!
That light bulb chart is bogus. A 400 watt HPS light uses the same amount of electricity as 4-100 watt incandescent bulbs. 400 watts is 400 watts and the kilowatt hours don't change just because one is HPS and the other CFL or incandescent or whatever; they are exactly the same.

 

I don't think it's an energy usage chart, it's comparing the strength in lumens.

 

Oh Ok. My bad. I thought it was an energy useage chart.

 

nah bro. It was showing that for the money spent on 400 WATTS, you get way more light out of a HPS light than you would out of another 400W light. So, to equal the lumen output of the HPS you better have 84 60W incans.