Chemical balance check up

With me losing my clam last night I just checked water parameters, as I should check on a more regular basis it seems like I'm checking every other week, as far as dosing I could be better with that especially with a job transfer a month ago that has me driving an hour farther from home and has made me not be as remembering as I'd like to but I just checked parameters:

Nitrates: no concern between 2-5 nothing really showing
Alk: 8.3ish
Calccium:460
Magnesium: 1100
Salinity 1.028-1.029

Know I need to raise mag/lower salinity a bit but i don't think anything is too far off...I never check for phosphates, never have in the 3/4 yrs I've had my tanks set up.

Lighting changed last October to LEDs but would think I should have seen any negative affects by now...water flow stayed the same, just wanted to make sure I'm not missing anything, as I want the best for my tank and inhabitants...sucks losing stuff, that's all I know and I don't want to lose stuff cause of what I am doing.

 

You saw nothing going on with your clam before it's demise?

 

Are you using a refractometer to check that SG?

 

A little of the mantle was gone a couple weeks ago and looked good yesterday morning then my emerald crab was eating it last night...yes using a refractometer

 

Just curious, why do you have your SG so high?

 

sounds like his auto top off took the day off!