PH to high

[Raineesman]

I Have had my aquarium for about 3 months now. I need some advise as how to lower my PH.
Ever since i started it has been around 8.5 as far as i can tell. I have a hagan test kit and im not real happy with the PH test, its not real deffinate.
Anyway i tested my carbonate hardness last night and it was sky high, around 400.
What can i do to take care of this problem?

 

[kau_cinta_ku]

this article should tell you all you need to know.
High pH: Causes and Cures