Help! Plate corals not doing so well

[shadow62672]

My orange and green started to take a turn. Not sure what is going on. They have been healthy up till today. Woke up to this. Any idea?
PH 8.1, Ammonia 0.1,Nitrite 0, Nitrate 5, Salinity 1.024, phosphate 0.25, calcium 440, Alkalinity 5.9.

 

[shadow62672]

Here are pics how they looked about 3 days ago to a week.

 

[DIAZ REEF]

I’m not familiar with this coral in particular but I believe your alkalinity is way low. 8.5-9 is where you want it.
magnesium ?

 

[shadow62672]

I’m not familiar with this coral in particular but I believe your alkalinity is way low. 8.5-9 is where you want

I’m not familiar with this coral in particular but I believe your alkalinity is way low. 8.5-9 is where you want it.
magnesium ?

Good suggestion, I will adjust that. Anyone else have plates and dealt with this?

 

[DIAZ REEF]

Good suggestion, I will adjust that. Anyone else have plates and dealt with this?

Remember, do it slowlyyyy