tek light issues (ballast?)

[Skimmer Juice]

swapping bulbs was the first thing I did. So its not the bulbs for sure. Like I said the switch power comes on , just no bulbs light up. Just haveing a hard time finding what ballast I shoud order . But now that you mention it the numbers you pointed out are probably correct so I will assume its the one with the #4 . So i will try that one first.