I think the 430W will work fine with the 400W ballast. HPS both bulbs, right? Go for it.

Or, try and post a message in LateWood's thread... he's the electrical wiz.
turtle420 Reviewed by turtle420 on . Which Light To Use? Is There A Difference? PICS Hello again everyone, I was wondering if there is a difference in 400w HPS lights. My buddy gave me 6 bulbs that say "LUMALUX LU400 SYLVANIA" He also gave me one bulb that says "PHILIPS 430w SON AGRO" My ballast is a 400w HPS. Would one of these be better to use than the other. Also, ive heard that older bulbs can have different effects on your plants etc. How should i choose which one to use out of the six? Picture: One HPS is already in my ballast and not shown, but in the pic, the 5 Rating: 5