get a low watt MH or 6-8 4ft floros (minimum)to keep them alive(don't forget the mylar!), you'd need 20-30 cfls to keep that number alive, and a 4x4 space wont be enough for 13 plants (I have 4 barely in that much space), cut your number of plants in half or double the space; you'd be surprised how large and bushy mothers get especially when they've been alive for 6 months or more.