Morri
Fish Herder
All salts are pretty much the same but I prefer the D&D I think a lot of people use it roughly 50quid for 23kg
if your SG is low this could cause the CA to read low but that is way low
Test the CA of the saltwater from your LFS
if your SG is low this could cause the CA to read low but that is way low
Test the CA of the saltwater from your LFS