Question on lighting nedd help please!

OOkay so I jus finished the 4th week of flower and my step dad came over today and gave me his old light. Its a 400 watt mh ericson indrustial bay light. My question is if I add this to my grow area will this give me a better yeild or jus cost me extra money on my power bill?

get a cmh bulb for it it will kick ass

philips allstart 330

http://advancedtechlighting.com/cdmallstart.htm

I would just use that MH to veg.

What size light are they under now?

Im under a 400 watt mh rite now. Its all I had but they are doing great for all the bad rap every lone gives them

I would use what you have at the moment but I would plan on getting hps for flowering when you can. The biggest difference is the lumen output from mh to hps. a 400 watt mh puts out around 36,000 lumens and has a life of around 10,000 hours a hps on the other hand puts out around 48,000 lumens and has a life of 20,000 hours so you gain a extra 12,000 lumens while using the same amount of electricity.

I've read that a mixture of both HPS and MH during flower is beneficial