How to Correct a PH Imbalance in a Tank

The measure of acidity or alkalinity of the water is in your fish tank is known as it pH. The pH scale runs from 0, the most acidic, to 14, the most basic. A reading of 7 is neutral. The levels are important to monitor because all organisms thrive in relatively narrow ranges on the pH scale. Fresh water tanks should maintain pH levels between 6.6 and 7.8 with saltwater reef tanks being slightly more acidic with pH levels of between 7.8 and 8.5. Adjusting the pH level can be achieved by a trip to the local pet supply store.

Things You'll Need

  • pH test strips
  • pH up chemical
  • pH down chemicals
  • Lemon juice
  • Water
  • Declorinator
Show More

Instructions

  1. Low pH

    • 1

      Test the water with a pH test strip purchased at a fish supply store. Use the strip as directed to confirm low pH readings.

    • 2

      Add a chemical to the water to raise the pH of the tank such as pH up products which are located in the pet supply store. Follow the directions on the product when adding to the tank.

    • 3

      Monitor pH levels in the tank closely for the next few weeks to identify reasons why the tank may have low pH levels. These may include calcium carbonate/carbon dioxide reactors malfunctioning and releasing too much carbon dioxide back into the tank. Adjustments to the reactor can be made, however, tanks with reactors will run on the lower pH levels.

    • 4

      Open the windows around the tank if possible to remove excess carbon dioxide from the tank area. If the tank is in a poorly ventilated area, carbon dioxide can build up and enter into the tank lowering pH levels.

    • 5

      Complete a partial water change on the tank to lower the pH level present. Take out no more than 20 percent of the water and replace it. If using tap water, make sure to use dechlorinator tablets before adding the water to the tank.

    pH Too High

    • 6

      Test the water with a pH testing strip to confirm the pH level of the tank is too high. Using too many chemicals when trying to raise pH levels or overusing pH alkalinity supplements may cause high pH levels.

    • 7

      Add pH down chemicals to the tank. Adding a small amount of natural acid such as lemon juice can drop the pH in the tank quickly if the levels are dangerously high, such as exceeding 10.

    • 8

      Complete a partial water change on the tank to lower the pH level present. Take out no more than 20 percent of the water and replace it. If using tap water, make sure to use dechlorinator tablets before adding the water to the tank.

    • 9

      Monitor the pH levels closely over the next few days to make certain the pH level has returned to acceptable levels.