I am having problems with one of my 400w PFO pendants (see other posts searching for a ballast :angry). One of my 10Ks won't light reliably, so I figured it was the ballast. Premium Aquatics pointed me towards the bulb, so I switched Ballasts and the problem followed the bulb & not the ballast. According to Premium: "Ushio has worked with PFO for over 7 years, but recently Ushio has had more problems, we believe they redesigned their bulb. Seems a few of the higher quality German lamps are having trouble firing on standard magnetic ballasts."

I have three other Ushio 400w 10Ks that are working fine, but am worried they may start acting up too?

So ... what 400w 10K bulb would y'all recommend to run on a standard PFO magnetic ballast?