How to Restore Alkaline pH Balance in an Aquarium

Maintaining a consistent, appropriate pH in your aquarium is more important than achieving an exact, optimal pH measurement. The pH scale runs from 0 to 14, and on this scale, 0 is the most acidic, 7 is neutral, and 14 is the most alkaline. Many freshwater fish can survive anything from 5 to 9, while saltwater tanks need to run between 8 and 8.5. If your tank begins to run too far toward acidic, you will need to take steps to restore alkalinity.

Things You'll Need

  • Gravel vacuum
  • Chemical for raising buffering capacity
  • Chemical for raising pH
  • Limestone or crushed coral
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Instructions

    • 1

      Change 30 percent of your water volume, vacuuming your substrate well. You will need to perform this water changes routinely. For a freshwater tank, use dechlorinated tap water rather than distilled or reverse osmosis water, as most tap water has an alkaline pH.

    • 2

      Clean your filtration devices and make certain they are working properly. Proper filtration raises your tank's "buffering capacity;" in other words, your tank's ability to maintain its pH.

    • 3

      Add a chemical additive, sold in most pet stores, that will raise the buffering capacity of your aquarium water. Raising the pH in a tank with insufficient buffering capacity is useless, as the pH will quickly drop again. Follow dosage instructions for the product you have purchased.

    • 4

      Add a chemical such as "pH-Up," which helps raise pH levels in aquariums. Follow the dosage instructions on the packaging.

    • 5

      Increase the water flow and movement in your tank by turning up or replacing your pumps with higher flow pumps. Aerating devices also help agitate water.

    • 6

      Add limestone or crushed coral to your gravel or filtration. These rocks add to the alkalinity of your tank.