How to Keep a 40-Gallon Fish Tank Clean

One of the joys of owning tropical fish is knowing your fish are happy and healthy in good environment. Cloudy glass, green-tinted water and algae-covered tank ornaments defeat the purpose of having an aesthetically pleasing, relaxing aquarium. Providing a safe home for your pets requires minimal care on your part. The key to keeping a 40-gallon fish tank clean is consistent water changes to remove the build up of harmful nitrates from the water. Regular maintenance every two weeks will keep your tank clean, algae to a minimum and your water sparkling and clear.

Things You'll Need

  • Tap water conditioner
  • Replacement filter cartridges
  • Long-handled tank glass scrubber
  • Bucket
  • Fish tank siphon/vacuum
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Instructions

    • 1

      Unplug your tank heater 15 minutes before performing any water changes. You'll ruin the heater if you forget this step, and it can result in shattered glass in your tank.

    • 2

      Change 33 percent (13 gallons) of the water every two weeks. Grab a bucket and hook up your siphon to remove the water from the tank. Fish tank vacuums suction the water out of the tank. The suction will remove some of the algae and fish waste while the screens in the siphon prevent suctioning of fish. Start the vacuum by simply pumping the tube full of water using an up and down motion in the tank. Once the siphon starts, drain the water into a bucket. Make sure to stop the suction or place the end of the drain tube back into the tank before emptying the bucket.

    • 3

      Scrub the sides of the aquarium with the long-handled tank brush, if necessary. These brushes are designed to clean algae from the glass without damaging the protective finish. Pet stores also sell magnetic glass cleaners for use in cleaning tank glass.

    • 4

      Check your filter cartridges. If they are scummy and brown, unplug and remove the entire power filter. Rinse the filter components with hot water, scrubbing the components, if necessary. Throw out the old filter cartridges and replace with new, making sure to rinse any charcoal completely before installing them. Remember that cleaner tanks require fewer cartridge changes. You'll see a marked decrease in cartridge use with more frequent water changes.

    • 5

      Replace the filter components and clean filter cartridges. Reinstall the filter into the tank and prime the filter with clean water.

    • 6

      Refill the tank with water that has been treated with tap water conditioner to remove the chlorine and chloramine from the water. Chloramine and chlorine aren't harmful to humans, but can be deadly to your fish. Plug in your filter and heater and allow the filter time to recycle to the water in the tank. Your aquarium water should clear completely in 24 hours.

    • 7

      Clean your rocks and ornaments once every 6 months during a more thorough tank cleaning. Use the fish tank siphon to methodically work your way through the tank, suctioning the gravel into the vacuum. This removes the fish waste and dead algae that settles below the gravel bed through the siphon tube.

    • 8

      Purchase a "sucker fish." Plecostomus are algae eaters that help remove some kinds of algae. Frequent water changes help reduce the level of nitrate in your tank caused by fish waste. Nitrates can cause algae blooms and unhealthy water quality that can result in fish deaths and illness.