Lately i am having trouble raising my Calcium above 350.
Check your Mag level and your ALK
level, more than likely your Mag level is low and your alk
is high. The depressed Mag will prevent you from keeping the CA
in solution, your Mag should be in the 1200 - 1500 mg
/l range, even with a heavy coral load 4g per week on a 17g tank should be able to maintain CA
levels without any other supplamentation, unless the newly mixed SW
is out of balance