Changing the Water - Cleaning the Tank

Regular maintenance of your tank will keep your aquarium looking sharp and your fish healthy.

Bright colorful fish swimming vigorously in a tank can be a great addition to any home and is usually the reason many of us choose fish as pets. Unfortunately, fish tanks accumulate grime and need some attention to keep clean. Follow these tips on how to clean a fish tank and maintaining your tank should be simple and straight-forward.

Things You Will Need

  • Algae scraper or pad
  • Bleach
  • Bucket
  • Container to temporarily house fish
  • Chlorine or chloramine remover, water conditioner
  • Cup or bowl
  • Filter media,
  • Fish net
  • Gravel vacuum/siphon
  • Paper towels
  • Properly prepared water in the quantity you'll need to replace


Once a week, you should remove about 10% of the water from your tank and replace it with clean water. If you do this substitution on a regular basis, the frequency with which you will need to clean your tank will be minimized. Once this substitution is not sufficient to keep your tank looking fresh, you will need to conduct a thorough cleaning as follows:

Steps for Cleaning

  1. Read through these steps. Check the list of supplies you will need and make sure you have everything ready.
  2. Unplug all electrical items connected to your tank.
  3. Remove the lid and wipe it down, setting it aside when finished.
  4. Scoop some water from the tank into a container to hold your fish while you are cleaning the tank.
  5. Use the fish net and gently remove your fish from the tank, placing them in the container you just filled.
  6. If your decorations are covered with algae, remove them and give them a thorough scrubbing in a solution of water with 2% chlorine bleach added. Rinse thoroughly.
  7. Use an algae scrubber to remove algae from the walls of the tank.
  8. Start the siphon and direct the water you are removing into your bucket. Remove, at most, 50% of the water from your tank. Typically, 25% is sufficient.
  9. Push the gravel vacuum through the gravel, stirring up any excess fish food and waste. Note the amount of extra food you think you are seeing. If there is a lot, consider feeding your fish less frequently or smaller quantities.
  10. If you have sand on the bottom of your tank instead of gravel, do not send the sand through it. Stir up the sand and then suck up any debris that may be floating about the lower surface.
  11. Check your filter cartridge and rinse it off if necessary.
  12. Replace the water you removed with fresh, treated water at the same temperature of the aquarium. Any cloudiness will dissipate in a few hours.
  13. Place your fish back in the tank when you think it is ready.
  14. Sit back and enjoy your clean tank.


Some Tips and Warnings

  • Always wash your hands thoroughly before and after cleaning your tank.
  • Be sure to rinse all of your equipment in hot water after using it as well. Hot water will help kill any bacteria before you store it away.
  • Letting the water sit for a few hours will neutralize the chlorine in your tap, but not the chloramines, which are just as harmful. Do your fish a favor and use a water conditioner.
  • Only net your fish to remove them if it is necessary. Less handling means less stress for your fish.