Hello
Try this cart for stable system I noted in my tank that you may see the PH and ALK come down by raising Cal but also consider checking mag.
as raising Cal could be expensive if Mag is not correct
also i noted with my issue this cart is funny as it indicates that higher Cal corresponds with higher Alk. In my questioning i found that it is the consummation of Cal that my be lowering PH so Mag. testing may valuable to use this to lower PH.
Alk meq/L Alk dKH Calcium ppm
0------------0-----------360
0.5----------1.4---------370
1------------2.8---------380
1.5----------4.2---------390
2------------5.6---------400
2.5----------7---------410
3------------8.4---------420
3.5----------9.8---------430
4------------11.2---------440
4.5----------12.6---------450
5------------14---------460
5.5----------15.4---------470
6------------16.8---------480
6.5----------18.2---------490
7------------19.6---------500
Interesting web page for comparison of your salt mix with other brands
http://saltaquarium.about.com/gi/dy...om/fish2/aqfm/1999/mar/features/1/default.asp