Huge par difference in new bulbs

[xroads]

Hey all,

I switched over my 250 SPS tank to MH last month.

I used Galaxy electronic ballast & hamilton 400w bulbs.

At the surface my readings are 500, 900, & 725.

Why such a huge difference from one bulb to the next?

[luther1200]

Could be the ballsts or bulbs. Are the ballasts all brand new also? And are they using the same reflectors?

[xroads]

Yes, all 3 all new & all the same

[luther1200]

I would say its most likely the bulbs then. But I am not an expert, maybe some one else can chime in. Maybe they just need time to burn in.