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How to Change the PH of Water

| Updated September 26, 2017

Things You'll Need

  • Crushed coral

  • Mesh bag

  • Rubber band

  • Peat chips

  • Bowl of warm water

  • Strainer

Water pH is one of the most important aspects of quality water. It measures the alkalinity and acidity of water. Water pH is neutral at 7.0. A measurement below 7.0 is acidic and above 7.0 is alkaline. Fish owners may wish to adjust the pH of the tank water in accordance with what their type of fish prefers, which can be done quite easily with just a few additives depending on your desired pH. There is no need for expensive Alkaline Ionizers, machines used to adjust pH directly from your faucet, that can costs upward of $100.

Raising pH

Place the crushed coral in the mesh bag.

Close the bag and tie it shut with the rubber band.

Rinse the bag of crushed coral under your faucet to remove dust and loose particles.

Place the bag in the aquarium either in the filter or tucked away at the bottom of the tank.

Lowering pH

Place the peat chips in the bowl of warm water and soak overnight.

Strain the warm water from the chips.

Place the chips in the mesh bag.

Close the bag and tie it shut with the rubber band.

Place the bag of peat chips in the back of the filter so that filtered water runs through it.


  • The size of your tank, or the amount of water you're using, will determine how effectively the bag of coral or peat chips adjusts your pH. As a rule of thumb, a handful of chips or coral will adjust approximately 10 gallons of water by 2 degrees in either direction. For example, a handful of crushed coral will raise 10 gallons of water from 5.0 to 7.0 pH.