Can You Change a Fresh Water Tank to a Salt Water Tank?

Changing a freshwater fish tank to a saltwater tank is more complicated than changing the water and adding saltwater fish. You'll need to overhaul the system, installing new lighting and substrate.

  1. Lighting

    • It's important to purchase high-powered lights essential to keeping your hard corals, soft corals and live rock alive. These can be compact fluorescent or metal halide. Ask your local fish store for guidance. It's not uncommon to spend $100 to $200, or more, on saltwater lighting.

    Substrate

    • Replace your freshwater substrate with a live substrate. A saltwater tank requires live sand, which is collected from the oceans and contains microorganisms and beneficial bacterial that improve water quality. Live sand also contains worms and crustaceans that break down waste material and act as a natural food source for your fish. Your fish store can help determine how much live sand you should purchase.

    Live Rock

    • Build your new reef using live rock. You will need about 1 1/2 lbs.. of live rock per gallon of water.
      Live rock will serve as a natural filter in your tank. It comes from the ocean and is full of beneficial organisms that add biodiversity to your tank. Live rock should be cured before installation, and most fish stores supply pre-cured rock. Some of the more popular live rock varieties are Fiji Premium, Fiji Fancy Branch, and Caribbean Live Rock.

    Ask A Professional

    • Consult your local fish store during the conversion process. Your local saltwater expert can provide in-depth information on the complete process of changing over your freshwater tank. Research articles or read books on the process of setting up and maintaining a saltwater tank. This process can be quite expensive. Depending on the equiment you choose the cost can range from $200 to $500.