Hi Priscilla,
from me too.
I agree with Ann, if you can upload a photo it may help in identifying the problem with your
Christmas Cactus (Schlumbergera truncata). My first thought was possibly water spots but if none of your other Schlumbergera have the white spot problem and if there are no pests present and it's not due to an environmental issue (like sunburn or sudden change in temperature) the only thing I can think of is a possible fungal infection. I googled and found this photo for comparison with what you have on your plants:
http://www.bing.com/images/sea...
Member
@JB grows the Holiday Cactus and may be able to offer advice.
