Hammer coral not opening

[Hebrewhammer]

Hi there I'll start by saying I was told this was a hammer coral or hammer frogspawn hybrid. The seller convinced me I could grow it just as easily as softies. Well my leather I bought from him is doing amazing and this little guy seems finicky. It closed after the 2nd dally being in my tank.

Ph 8
Kh 6.79
Nitrates 15

I know my nitrates are a little high but I am planning on trying to doing a bigger water change this weekend.

 

[Jekyl]

Tank looks very new. Euphylia will be hard to keep at this point. Your alkalinity is low and you're lacking a calcium, magnesium and phosphate test

 

[Cali Reef Life]

Just to add on to what he says you should also monitor your salinity its the most over looked and easiest to test for.

 

[Jekyl]

Pic is blurry. Is the tissue already retracted with the skeleton showing on top?