250W HPS bulb

I Just got a 250W HPS bulb would one of those be enough for 4 plants?

How Many Watts Do I Need?

The general rule of thumb for providing light for an area is a minimum of 30 W per square foot. 50 W per square foot is optimal. You can determine the proper lighting for your area by using this formula:
For example, say you have an area of 10 square feet and a 30 W. That would mean you have a 300 W per square feet minimum. Also, remember that fluorescent's are weaker and emit less light than an HID. This means you will need 5 times the amount of wattage to equal the output of an HID. So, 30 W of HID would equal 150 W of fluorescent's.

Its enough for four plants in a 2x2 area. I started out growing nine plants in one gallon pots in a 2.5 x 2.5 area. It worked out OK. There is a big improvment in upgrading to a 430 hps and a HUGE improvment moving up to a 600 hps. After that, moving up to a 1000 hps, the heat issue becomes way too great in that small of an area, even with ventilation. But the 250 is a great way to get started and beats the bejeezus out of fluros, IMHO.

Vi