Mine would stop pulsing whenever the PH dropped bellow 8.2 ish which it hasn't done in six months or so. I wasn't so much worried about how unhappy it looked. It was the enormous wound in the top of it and the cleaner shrimp happily shredding chunks off that had me wondering. That seemed to explain the unhappiness. Just to be safe, I will test the parameters again when I get home this afternoon.