How to Increase the pH in a Fish Tank

The desired pH in a fish tank depends on the type of fish you have. While some fish prefer an acidic environment, others prefer a more alkaline setting. PH levels range from 0 to 14, a scale in which higher numbers are alkaline, lower numbers are acidic and seven is neutral. Various chemical processes occur in a fish tank that can decrease the pH level. Frequent monitoring of the pH level in the fish tank lets you know when it is time to increase the pH level to create a more hospitable environment for your fish. Most fish prefer a pH range of 6.4 to 7.8.

Things You'll Need

Disposable pH test strips
Coral sand, crushed coral, limestone and/or sea shells
Baking soda

Instructions

- 1
  Test the pH level in the tank regularly using disposable pH test strips. These are an inexpensive way to test the water.
- 2
  Add natural ingredients to the tank to increase pH if it needs adjusting. Sea shells, limestone, crushed coral and coral sand all increase pH. Some people place the crushed coral in a mesh bag. Add only one of these ingredients to start. Pour in about 1/2 tsp. at a time so the pH level rises gradually. Test the water with a pH test strip about 15 minutes later, then keep adding small amounts of the natural ingredient until you attain the desired pH.
- 3
  Add baking soda to the fish tank as another way to increase pH. Use 1 tsp. for every 5 gallons of water, adding 1 tsp. at a time. Test the pH level before adding more baking soda. Do this until you get the pH level you want. Using baking soda is not something you just add once to the tank. If you use baking soda, you must test the water on a daily basis adding small amounts as needed.
- 4
  Use a pH increaser as another alternative. Pet stores sell these liquid products to increase the pH level of aquariums. Follow the directions on the label carefully.
- 5
  Increase the pH level of the water gradually. Sudden changes in pH are harmful to fish.