How to Clean a Fish Tank After High Ammonia Levels

High ammonia levels in a fish tank can occur for a variety of reasons. Most often high ammonia levels result when too many fish inhabit a fish tank. Overfeeding and the use of certain fish medications can also cause ammonia levels in the tank to rise. The scenario can happen in a new setup and in an established tank, causing your fish to die of ammonia poisoning. Once you have tested the water with a standard testing kit, and determined that the ammonia levels have risen above 1ppm, you will need to take quick action, treating and cleaning to save the tank.

Things You'll Need

  • Ammonia removal product
  • Nitrifying bacteria cultures
  • Fish net
  • Aquarium tweezers
  • Gravel vacuum
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Instructions

    • 1

      Apply an ammonia removal product to the tank. Purchase the product from the pet store and add according to manufacturer̵7;s instructions. If you use tap water to fill your tank, use a product that removes both ammonia and chlorine.

    • 2

      Build up the good bacteria in the fish tank by adding nitrifying bacteria cultures. Also purchased from a pet store, this product will help to break down ammonia in the fish tank when added according to label instructions.

    • 3

      Check the fish tank for dead fish and remove them with a fish net. Decaying carcasses will cause ammonia levels to rise in the tank. Make sure that you look underneath the decorative features in the tank, too. Dead fish sometimes decay under rocks.

    • 4

      Remove all of the dead plant life in the tank. If you have live plants in the fish tank, immediately remove them when they die. Dying plants can cause ammonia levels to rise. Pull out dead plants with aquarium tweezers. If you experience continuous problems with dying plants, consider replacing them with artificial.

    • 5

      Vacuum the gravel at the bottom of the fish tank using a gravel vacuum. When you overfeed fish, the uneaten food settles to the bottom of the tank. When it breaks down, it can cause a rise in ammonia levels. Cleaning the gravel with the gravel vacuum can remove the excess food.