Flockshot -- you're right on -- I have a small tent, I think it is 2 ft by 2.5ft but 8ft high. So I have 2 Northern Light auto's -- just natural, no LST, and they are now 34 -36 inches tall. So those 2, plus a fan, plus a humidifier and I'm out of room. Luckily I have the height for my 2 300 watt leds -- plus the heat can be a problem at times.
Now next grow I will rearrange a bit, and I might be able to get 3 plants in.
A least try to get more height Pakweezy, or like Flockshot said, look into cfls.