How do I increase alkalinity in my aquarium naturally?
Baking soda (sodium bicarbonate NaHCO₃) increases the KH and pH of water. You can add 1 teaspoon of baking soda per 5 gallons (19 liters) of water.
What happens if alkalinity is too low in fish tank?
Algae growth, sludge/dirt at the bottom of the fish tank, sudden changes in your fish’s appearance and behavior, are all signs that your aquarium’s pH (alkalinity) has dropped too low.
What increases alkalinity in water?
If the landscape is in an area containing rocks such as limestone then the runoff picks up chemicals such as calcium carbonate (CaCO3), which raises the pH and alkalinity of the water. In areas where the geology contains large amounts of granite, for instance, lakes will have a lower alkalinity.