150 watt hps

What can i do with a 150watt high pressure sodium light fixture. How many plants can i grow in a DWC setup. I am refering to my current hydro grow.

Will it raise 3 plants?

I read that I must have at least 3000 lumens/ sq foot. I have 6 sq feet of closet space and am currently running a 150W HPS which puts out 16,000 lumens.

I can get another 150W HPS for 70 bucks... or a 400 W HPS for 170 bucks and then replace my current 150 w hps.. but then ill be broke and i wont be able to pay my rent