Help calcium and Ph problems

[oddiseus]

Ok so here is the deal. No matter how much dosing of Bionic I do I cannot get my calcium levels in the right spot. I also do daily additions of a ph buffer because my RO water comes our real low in Ph. The RO/DI unit is a 7 stage unit. Is this the reason why my params are out of whack. My tank has not grown 1 pinch of coraline in its life (6 months) It also kills coraline coming in off of other frags. Might you guys know what is going on in my tank? And how can I fix it?

 

[BLKTANG]

What salt mix r u using?

IMO,i would buy distilled water for a better ph reading.

 

[oddiseus]

I use instant ocean.
I dont buy water, I have an RO/DI unit