CRW Reef;180299 said:
Hey Mike, in this thread Derek (aka thatoneguy) is talking about baking soda lowering pH when used by itself. Might be source of issue for you.
http://www.marinecolorado.org/forums/showthread.php?t=13583
http://www.marinecolorado.org/forums/showthread.php?t=13583