Leathers in Trouble-Picture included for help...

[confusedfishy]

My coral aquarium is 65 gallons. I have many different types of coral, for example...mushrooms, bubble, starburst, gorgonia, button polyps, etc...
I also have, what I believe to be some different leathers. For the last few days they have not seemed to be right-see picture! The other corals and fish in tank all seem fine, the water test results are below. I am not sure what is wrong with these 2 corals. Any suggestions would be great!!!!
Ph-8.4
Nitrite-0.0
Nitrate-18.0
Ammonia-0.0
Calcium-appx. 450
Salinity-1.023 (barely)

 

[reefmate75]

raise SG to 25-27, NO3 is kinda high
leathers can some times shead and they will not polyp out properly untill they are done, my toadstool dose this every so often, i wouldnt worry to much enless you are seeing dark patchs, dark patches are dead parts on the leather and i normally clean that part off as it will fall right off ive noticed if you rub that area there will be a rotten spot like on a potato and will leave a creater but it will heal up fast but from your picture i cant really make out any dead spots, and im not going to say there isnt any though