if you add kalk should your Ph go up?

[Aquattro]

Ross, a common error people make is adding full strength kalk, even if they don't need it. Do you have a high Ca demand? If not, mix the kalk half strength and your pH should sit in a normal range. 8.6 is getting a bit high. BTW, you can measure your Ca demand by taking measurements 24 hours apart (without adding additional Ca). This will tell you your daily consumption and you can dose kalk accordingly.