Simple definition: pH measures how acidic or alkaline pond water is, on a scale where 7 is neutral.
Detailed Explanation
Most pond fish tolerate a fairly wide pH range, but sudden swings are more dangerous than a stable value slightly outside the ideal range. pH tends to drift lower over time as the nitrogen cycle produces acidic byproducts.
Why It Matters
Rapid pH swings, more than the exact number, are what stress or kill fish. A pond that’s consistently at 6.5 is usually safer than one swinging between 6.5 and 8.5 in a day.
Practical Example
Testing pH at the same time each day matters, since it naturally rises during daylight (plants and algae photosynthesizing) and falls overnight.
Related Terms
General Hardness (GH)
