How to Make R/O Water Suitable for Fish

Written by justin otto
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How to Make R/O Water Suitable for Fish
. (RomoloTavani/iStock/Getty Images)

In aquarium terms, R/O water is water that has passed through a reverse osmosis filtration system. This type of filtration system removes impurities and heavy metals from the water, making it safer for aquatic life. When these compounds are present in an aquarium system, they can lead to unsightly algae blooms. There are steps that should be taken to prepare such water for use in an aquarium environment.

Things you need

  • PH up and down chemicals
  • Synthetic sea salt
  • Large container, such as a clean dustbin
  • Water pump for mixing
  • PH test kit

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  1. 1

    Run the system until the desired amount of water is collected in the container that you have chosen.

  2. 2

    For saltwater aquariums, mix one cup of synthetic sea salt, such as Instant Ocean, to every 2 gallons of water in the container. R/O systems strip all pH from the water during the filtration process, but the synthetic salt contains a pH and alkalinity buffer that will leave your water's pH and alkalinity at stable levels.

  3. 3

    For freshwater tanks, test the water that has been filtered with the pH test kit and, following the directions on the bottle of pH adjuster, apply as directed until the correct pH for your specific water environment has been attained.

  4. 4

    Place the pump into the container and plug it into a receptacle. Let this sit overnight to mix the salt or pH adjuster into the water thoroughly. This will ensure that the water balance is perfect.

  5. 5

    Place the correctly adjusted water into the aquarium and test the pH and alkalinity again to ensure that they are at the desired levels.

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