How to Stop Evaporation in My Fish Tank

While feeding your fish one day, you notice that the tank's water level seems lower than usual. Concerned, you search the tank's edges for leaks and the hoses for proper circulation. You stand puzzled for a minute or so, and then it hits you -- the water must be evaporating from the tank. Evaporation is a completely normal and natural process that affects any body of water, aquariums and fish tanks included. While there is no sure-fire way of stopping evaporation, there are several tips you can use to monitor and reduce it.

Things You'll Need

  • Colored tape
  • Fish tank cover
  • Room humidifier
  • Large plastic bucket
  • Thermometer
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Instructions

    • 1

      Place a piece of colored tape at your tank's maximum water level, or the level that the water usually rests at when the tank is fully filled. This will help you monitor how much water evaporates daily or weekly.

    • 2

      Install a suitable cover for your tank. The ideal cover is one that can handle high amounts of condensation and has few ventilation ports -- this prevents water from escaping and allows it to drip back into the tank once condensed.

    • 3

      Relocate your tank to a less drafty, more humid room. Placing your tank next to large open windows or underneath powerful ceiling fans invites rapid evaporation to occur. Also, a room with dry air will deplete your tank of its water very quickly. Try storing it near a humid location like the bathroom or kitchen or use a small room humidifier.

    • 4

      Refill the tank as needed using aged tap water. To age the water, simply fill a large plastic bucket at your tap and let it sit undisturbed at room temperature for a week. Use a thermometer to ensure that the temperature of the water in the bucket and that of the tank water match or are within several degrees of each other.