Galaxea Help

[New2reef]

I have had this Galaxea for 3 months, but over the past 2 weeks, it has gone downhill, partial opening and visible stalks. I target feed mysis or oyster once a week

125 gallon
salinity 1.024
pH 8.2
ammonia 0
nitrite 0
nitrate 5
phosphate 0
dkh 9.0
calcium 425
magnesium 1140
lighting 5 T5, 3 actinic, 2 white
2 Tunze pumps

I change 20 gallons weekly. Other corals, leathers, frogspawn, zoanthid, bubble coral, feather dusters, all ok. I have 2 clownfish, a diamond watch goby, and Midas Blenny. the Galaxea is 3/4 up and not near anything else. any advice? Thank you!

 

[mr_X]

What lighting are you keeping it under and have you changed anything recently?

 

[New2reef]

I have 3 54 watt actinic white T5 (4 ft) and 2 actinic blue, all with reflectors

Thanks Doug
Christy

 

[mr_X]

What have you changed recently? dosing?