The purchase price is the smallest part of the total cost of a garden’s light. The biggest cost is running the light ? the electric bill.
A 400-watt lamp uses only 40% of the current that a 1000-watt lamp uses. However, a 1000-watt lamp will more than double a garden’s yield from what a 400-watt lamp can produce, when the plants are provided with adequate amounts of CO2 and nutrients.
The 400-watt and 1000-watt lamps are both good values depending on the size of the garden and the budget of the gardener. A 1000-watt lamp will require more electricity but will give a better yield. These factors are more important in the cost-benefit analysis.
Even if it is a little more costly to purchase, a 1000-watt HPS lamp would provide the best yield and be the best buy in the long run. The electricity use is the same as a 1000-watt MH, but the HPS produces much more light in the useable spectrum, increasing the garden’s efficiency by approximately 15%.
Readers with grow questions (or answers) should send them to Ed at: Ask Ed, PMB 147, 530 Divisadero St., San Francisco, California 94117, USA. You can also email Ed at [email protected], and send queries via his websites at www.ask-ed.net. All featured questions will be rewarded with a copy of Ed’s book, The Big Book of Buds. Sorry, Ed cannot send personal replies to your questions.