A lot of bleaching that happens is due to temp and lighting, but it could be an infection? But without knowing what caused the infection, there’s not much you can do. I wouldn’t do any dips, as that will cause more stress. What halide bulbs are you using? I tried some cheap Chinese bulbs and they really dropped in output after about 6 months. I just picked up some Ushio bulbs, which are going in ASAP.