adding light

I just bought a 400w hps light to add to my room .i have 4 150hps inthere already my question is can I just addtotal watts and that is what I am lighting my room with 4x150+400=1000w hps total?

hell yea the more light the better

that will tell you how manny watts are in there but remember that the 150s dont have the penetration of the 400

so its 1000w but the intensity isnt a 1000w. I put the 400 in the middle and I placed the 150s in the areas not as bright. kind of a secondary light. I wish I knew how to post pictures because i have been pretty impressed at my growth and budding so far. this is my second grow fromclones I had of some bag seed. the best bagged seed I ever smoked. believe it or not it was better because I grew it....LOL or I justtook better care

How big is the area you are growing in? if the 400 covers it sufficiently the 150's might be adding more heat then the extra light is worth.

my area is 6x4 8 feet tall it is airconditioned in thebasement never gets over 75. it has fresh air intake and is vented outside the room. I use two 12 inch ocial laying fans for air movement with inthe room

Can you explain what you mean about penetration. I guess I'll try the 250+150 but it sounds like it won't be as good as one 400???