How to Adjust the pH in Water Naturally

If you own an aquarium, you may have concerns about the pH level of your water. Most fish thrive in water that has a base pH of 7.0, but you may have fish that prefer a pH level that is much higher or lower. If you want to adjust the pH of the aquarium's water, you may want to do so naturally to avoid harming or poisoning the fish with chemicals. The water in an aquarium can be adjusted by adding natural objects, such as seashells, coral or wood.

Things You'll Need

  • Crushed coral
  • Mesh bag
  • Seashells
  • Small piece of wood
  • Peat
Show More

Instructions

    • 1

      Insert crushed coral into your fish tank or aquarium to raise the pH of the water. For a 40-gallon tank, pour one kilogram of coral into a small mesh bag, then place the bag underneath the gravel substrate on the bottom of the tank. You may also put the bag in the aquarium's power filter.

    • 2

      Increase the pH level by adding a few seashells to the water if you do not have any crushed coral on hand. Any type of seashells may be used.

    • 3

      Lower the pH of the tank water by adding a piece or two of decorative wood. You may also put a small amount of peat into the tank's filter. Doing so, however, turns the water a shade of brown or yellow, although this does not harm your fish.