Help!! with my Hammer

[nyc reefer]

I've had a purple hammer coral for over 5mons. When I first got it, it was great, it was plump and pumped/very healthy. I've made a few changes to my system went w/ a refugium, eliminated my 3 Koralias and started using a vortech gen 2 w/wavemaker, started dosing (2)part and upgraded lights from PC (192watts) to T5HO (156watts) w/ all Geisemann bulbs, changed salts from IO to Red Sea Coral Pro.
The problem is that the hammer has shrunk in size, it doesn't pump and looks like its eroding. I will post a pic tomorrow of how it looks under the lights.
Please help, advise me with whats wrong.

Ammo - 0ppm, Nitrite - 0ppm, Nitrate-20ppm, Salinity - 1.027, PH -8.3,
Cal. - 410ppm

 

[ZANYMASTER]

Test for Alk?They do react to sudden changes like most corals.Dose Iodine to try to pep it up.

 

[KathyC]

Always test for anything that you are dosing!
How recently did you change the lighting?
How long ago did you start dosing? How much are you dosing & what is the tank size?
Has the hammer been slowly declining or is it a sudden change?
What type of flow is it in and how high/low is it placed in the tank?

The Alk reading is really important to know.