pH & Alk problem - please help

[Twistedpro]

Hi,

I recently connected an aquarium computer to run my calcium reactor and test pH of my aquarium. I have been testing my the tank,

calcium is 440ppm, magnesium is 1250ppm, alk is 5.5 dKh tank pH is swinging from 7.6 morning 7.9 evening. I think my low alk is suppressing my pH. my Skimmer airline is fed from outside in freshair to blow off excess CO2.

I have tried raising Alk with baking soda and brought it to 8dKH leaving calcium and magnesium at their current leves, however the alk drops back down to 5.5 dKH. How can i keep my Alk at 8 without increasing calcium etc. If i bring my alk up will this keep my pH up?

[bertoni]

Bringing up the alkalinity should help. Dailing dosing is fairly normal. The calcium probably is dropping, too, it's just harder to detectd due to test kit limitations. I suspect the calcium reactor needs to be turned up. More aeration might help the pH.