I have a pulsing Xenia, (actually 3) but one that has grown t about 6 inches suddenly has a section where the tips looked singed , have turned white and seem to have blobbed about 1/8 inch. The other 2 are healthy. On the other side of the tank is a cluster of yellow polyp corals about 3 feet away, but all the other corals are ok. no changes in lighting, feeding, water cghanges, (10% a week) supplements, (Seachem 2 part and reefrhoids and iodine once a week) any Ideas? Salinity around 1.022, (have a real prob getting it up), Ca is 450 to 500, 9test kit error or Reef Crystals are always high,), no ammonia, no nitate, PO4 low ph is 8.0 or so. (The above solutions don't get it up. Have a 1 gallon refugium on a 29 gallon tank with lush growth of caulerpa..chaeto won't grow.) any ideas?