How to Test Rocks for Aquarium Safety

When putting items in your aquarium, you have to make sure ahead of time that they will be safe for your fish. Items like rocks can sometimes upset the water balance due to what they are made of, and this could make your fish sick or even kill them. With rocks there are certain types--such as lava and granite--that are better than others. But even then they should be tested to ensure that the stone is not mixed with other minerals that could cause harm.

Things You'll Need

  • Vinegar
  • Rocks
  • Water
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Instructions

    • 1

      Obtain the rocks you want to test. You will find them either in streams or fields, at landscape supply companies or aquarium stores.

    • 2

      Pour a small amount of vinegar on the rock and wait. Keep watching it. If it bubbles then it indicates that the stone will break down in the water, or that at least parts of it might.

    • 3

      Soak the rock in water for several days to dissolve any contaminants that might be compromising the vinegar test. Replace the water occasionally so that the contaminants won't settle back on the rock.

    • 4

      Test the rock again. If the vinegar bubbles this time, discard the rock and try a different kind.