Ricordea Yuma Help

[George Villasenor]

My Green-Purple Yuma recently started to 'poop' out a brown substance and shrink at least once a day, my orange-purple Yuma hasn't done this and they're both from the same lfs. I moved the green Yuma to a darker area and lower flow area or right next to the orange one. I read somewhere that it might be an infection that can cause it to 'melt' but the indication of a 'white substance' hasn't shown up on it, What should I do? Plus it's the most vibrant or healthiest looking coral in the tank and the events specifically happen when my Kessil lights are about to turn off.

Parameters [01-31-18]:
Alkalinity - 143.2 ppm
Phosphate - 0 ppm
Nitrate - 0 ppm
Calcium - 360 ppm
pH - 7.8
Magnesium - 1470 ppm
Salinity - 1.024

Been adding calcium supplement and Marine Buffer daily to raise the pH and calcium.

 

[reef lover]

Could be two things....the coral pooping or expelling zooanthellan which could b lighting or parameter related.