Water pH

pH Scale

pH is the measure of acidity or base of water. As you can see, the pH scale goes from 0-14. 7 is neutral.

Anything that is pH 0-6 is acidic and anything pH 8-14 is basic.

The scale is logarithmic, meaning each division is 10 times more than the previous one. For example, a pH of 2 is 10 times more acidic than a pH of 3.

The reason the pH level is so important is that each species of fish has a certain range of pH which they can survive. If the pH goes outside this range or fluctuates too wildly, the fish will die.

The main concern of aquarium owners is the acidity of the water. Fish tend to have a lower tolerance to acidic waters than basic waters (although water too base will kill fish just as readily).

There’s a class of chemicals called buffers (calcium and carbonates) that will act as a buffer to the pH levels of your tank, making sure that the pH doesn’t fluctuate too quickly and absorbing excess chemicals that cause pH levels to shift.

Coincidentally, these same buffers are often used as antacids.