How to Increase the pH Balance in an Aquarium

The term pH refers to the measurement of acidity or alkalinity in aquarium water using a scale that goes from acid at 1 to neutral at 7 to alkaline at 14. Most fish prefer pH around 6.0 to 8.5, and many fish can adapt to less-than-ideal pH. Creating a stable environment with stable pH is more important for fish health than providing the exact pH for the fish species. Producing a stable pH takes time and requires patience. Raising the pH too fast can cause pH shock and kill fish.

Things You'll Need

  • Aquarium water test kit
  • Ammonia remover
  • Limestone chips
  • Commercial pH up or pH stabilizer
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Instructions

    • 1

      Familiarize yourself with the pH and water chemistry requirements of your fish species.

    • 2

      Test the aquarium water̵7;s pH as well as the nitrite and nitrate ammonia levels. Compare your results to the charts included with the kit and the pH requirements for your fish species from step 1.

    • 3

      Retest the waters in 12 hours if the test results were not within a safe reading and again for a few days afterward to monitor if the levels stabilize. New aquariums go through a nitrogen cycle where the chemical levels spike, then stabilize. Make sure your tank is stable before adding any chemicals to the water, which could cause more problems.

    • 4

      Change 10 to 25 percent of the aquarium water every week with dechlorinated tap water, and then test the water. Tap water can raise the pH in aquarium water because it has been treated with calcium hydroxide, which makes the water slightly alkaline. Partial water changes will also raise pH by stabilizing ammonia spikes.

    • 5

      Treat the water with ammonia remover if your test results consistently show high ammonia and low pH. High ammonia can lower pH, and removing the ammonia will safely raise the pH.

    • 6

      Put limestone chips in the filter. Putting limestone, a source of calcium bicarbonate, in an aquarium creates a buffering system that raises the pH and creates a stable pH that will not spike in either direction. Limestone is not a quick fix, but you will see results in a few days.

    • 7

      Treat the water with commercial ̶0;pH up̶1; or a pH stabilizer as a last resort. Be aware, though, that these products can create an unstable environment and shock the fish.