I have a 4' 40/34w aquarium light that flickers nonstop when it's turned on. I have replaced the bulb with a F32T8/5500k daylight bulb. I have replaced the starter with a FS-4 13-30-40w starter the same as what was in there. It continues to have the same problem. What next? Not the ballast I hope. If it is then what size do I get as there are no marks or labels of any kind on it? Please help my fish out of their eternal darkness.