This picture shows different kinds of screw in bulbs.
HPS or High Pressure Sodium lights are commonly used as outdoor security lights. They put out light in the red and orange spectrum, ideal for flowering
MH or Metal Halide lights are used as security lights also. They put out light in a higher spectrum, ideal for vegetative growth.
CF or Compact Fluorescent lights come in many different spectrums. Some are Soft white (2700K), Warm white (3000K), White (3500K), Cool white (4100K), Full Spectrum (5000k), and Daylight (6500K).
Soft white (2700K) - yellow light, with a small amount of orange. Use for flowering
Warm white (3000K) - white/yellow spectrum. Use for flowering.
White (3500K) - white light with a small amount of yellow. Use for flowering
Cool white (4100K) - whiter than 3500K. Use for vegetative.
Full Spectrum (5000K) - very white light, some blue light also. Use for vegetative.
Daylight (6500K) - blue/white light. Use for vegetative.
These come in a variety of different lengths, diameters, and wattages. There are many different kinds of fixtures also. The fixture in picture 1 is something I made. I mounted the tubes to a 7" wide piece of wood. For reflection, I put a piece of 1" wide aluminum duct tape onto the top of the bulb. I heard about it on Overgrow. I am using cool white and soft white bulbs, 2 of each.
|The bulbs I am using are the most common. T12 meaning 1.5 in. diameter, 48" long, and 40 watts. The cool whites put out 3200 lumens, the soft whites put out 3300 lumens. A lumen is a measurement of the brightness of a bulb. Here is where the main problem with tubes falls. My 4 bulbs (picture 2) span 7" across, so if I took a 7" long segment of each bulb, and put 4 segments across, then I would have a 7" square of fluoro light. Each cool white bulb puts out approximately 67 lumens per inch, each soft white puts out 69 lumens per inch. So in the 7" square I only get about 1900 lumens. A 42 watt CF could put out 2900 lumens over the same area.||2.|
|Tubes are mounted on these simple sockets, which are easy to mount inside your box if you want. The wires can be lengthened, and you can remote the ballast, getting rid of a lot of heat in your grow room. Tubes work great, because they can be assembled into an arch, to completly surround a plant. This allows for all the light to be used, an the plants thrive.||3.|
|Picture 4 shows T12, T8, and T5 bulbs repectively. Common bulbs are 48" and 24" T12's, and 48" T8's. T5's are high in lumens, but will burn your plants. T8's are very good, and are ideal for growing, but are sometimes harder to come by in certain spectrums. They are 32 watts, and 3200 lumens, that's 100 lumens per watt. If you dont buy T8's i suggest using compact fluoros.||
image provided by sneakatoke