Hi Nathan, a lot would depend on your locale water source (assuming you use tap water) but perhaps you use rain water or RO treated water?
Generally speaking most people don’t get to concerned about the PH because they use what come out of the tap.
Folk who use injected C02 will see quite large fluctuations in the PH every single day because the C02 will drop the PH as much as 1-1.5 points.
However there are other things that can effect the PH like lime stone or certain woods.
I would say your PH is quite low, it would be good to know what your locale water board figures say about the PH of your tap water.