High PH, how to lower?

[Danh Ngo]

How to lower PH, my tank is sitting at 8.52 when lights on.
Dosing baking soda, vinegar?
How much should I dose?
Would I hurt the tank if I lower to 8.4 or 8.3
My monti is not happy

 

[Maritimer]

Vinegar will lower pH, but also add a carbon source. Go slowly.

~Bruce