Hammer losing one head at a time.

[dattack]

Anybody have any idea what can cause my hammer heads to slowly detached from its skeleton one at a time? I purchased a few frags of hammer coral and the head would slowly detached killing it.
Alkalinity and salinity has been stable at 1.025 and 8. I have dipped corals prior to placement in a tank that's been up almost 2 years. And visually inherent seen any flatworms.

 

[joseserrano]

What are your other#s, as well as any flow, lighting, filtration changes?

 

[dattack]

I have a 6 foot tank (60x30x24) with two ecotech vortech mp60Qd on both ends. Phosphate was kind of high at .5 ppm, running 3 G4 ecotech radions at 40 percent moreso blue. I did two water changes using redsea blue bucket at 20 percent because lost a small frag of hammer with 3 heads. The remaining frag with 2 heads is now slowly detaching a head. I am wondering if it's the flow since I moved it from the sand bed and onto the rocks which might be more flow. Phosphates level still at .2 ppm . I ordered salifert magnesium and will test that soon.

 

[dattack]

Tank