Yes, the alkalinity at 6 dkH is a low reading. Normally, I have been around 9 dkH ... didn't realize that would have such an effect. This is why the forum is so awesome!
BTW, I got this Galaxia from you as a free-be for buying some other corals. It has been healthy, happy and growing for about 18 months. I really want it to come back strong. Thanks!