I’m creating a relatively small cannabis growing chamber using compact fluorescent tubes for lighting. Are these lamps effective at all?
Compact fluorescent tubes are more efficient than conventional fluorescents. You can also place them near each other to increase the intensity of the light. Most of the tubes in these lamps have a “warm-white” spectrum which is generally adequate for vegetative growth and excellent for flowering. The marijuana buds will be potent and full of crystals.
Compact fluorescents with high wattage are capable of supplying ample light to a small garden and your electric bill might not take a significant hit. One 250-watt HPS lamp emits 28,000 lumens which would take four 105-watt and one 55-watt compacts to equal. These compact fluorescents would use nearly twice as much energy as the HPS. For an HPS lamp, you’re looking at about $21 per month during vegetative growth and $10.50 per month during flowering of your cannabis. With the comparable configuration of compact fluorescents, the costs rise to $34 and $17 per month respectively. It’s not a particularly large increase, and it might not matter to you. It really makes a difference with much larger gardens, though.
The heat that HPS lamps and their ballasts emit is rather notorious, because they use large amount of electricity. That energy is turned directly into either light or heat. A 250-watt HPS unit expends about 300 watts of energy in an hour while the fluorescents use 475 watts per hour. They produce more heat than the HPS lamp because they use more electricity and a higher percentage of that is turned into heat instead of light.
Even so, compact fluorescents are still adequate for light a small cannabis garden and are also rather convenient. HPS lamps produce around twice the light, but warm-white fluorescents emit a higher percentage of red and blue light than HPS lamps. Plants primarily use red and blue light so the amount of light that is useable to the plant is likely closer than the useable light figure would suggest.