Hammers losing color and not puffing up anymore

[TheStricklins]

Over the last month my 2 hammer corals have been opening but not puffing up near as big and the gold hammer has lost a ton of color. All other corals are doing great though, it's just the hammers. My nitrates were zero for a while but I have recently started dosing nitrates. Anyone have any suggestions to get it's color back and puffed back up? The 2 pictures are a month apart

Parameters are
nitrates- 10
Phosphates - 0
Alk - 10.2
Calcium - 440
Magnesium - 1350
Salinity - 1.026

 

[soreefed]

When my phosphates were zero my gold hammer was not very dark and looked somewhat translucent. It still would open up plenty, but as increased phosphate the hammer turned a deep purple with bright golden tips.