Low alkalinity water doesn't have capacity to buffers acids, and often is noticed by dropping pH.
Drift wood yes, but any form of metabolism produces acids that lower pH, (fish urine, by products of biological filtration, CO2 production by plants).
I find in low alkalinity tap water environments, even a somewhat small bioload can be significant.
Where with my Lake Michigan tap water, it may take a week before pH drop is noticed after a water change in a moderately stocked tank , someone in a soft water area might see a pH crash after only 2 days in a very lightly stocked aquarium (like yours). In Nevada where the water my come out of the tap at a pH of 8.6 and much higher alkalinity, it may take a month for a heavily stocked tank to see any significant drop in pH.
Its all about the base of the aquifer you live on, if the rock is granite your buffering capacity may be low, if the aquifer sits on dolomite rock (like mine) the carbonate produces a water often considered liquid rock.
Drift wood yes, but any form of metabolism produces acids that lower pH, (fish urine, by products of biological filtration, CO2 production by plants).
I find in low alkalinity tap water environments, even a somewhat small bioload can be significant.
Where with my Lake Michigan tap water, it may take a week before pH drop is noticed after a water change in a moderately stocked tank , someone in a soft water area might see a pH crash after only 2 days in a very lightly stocked aquarium (like yours). In Nevada where the water my come out of the tap at a pH of 8.6 and much higher alkalinity, it may take a month for a heavily stocked tank to see any significant drop in pH.
Its all about the base of the aquifer you live on, if the rock is granite your buffering capacity may be low, if the aquifer sits on dolomite rock (like mine) the carbonate produces a water often considered liquid rock.
