The Best Way to Clean a Fish Tank

A clean aquarium doesn’t only look great, but it also helps to preserve the health and happiness of your fish. This is because over time, nitrates and metabolites can build up, which can affect the appearance of your tank and the wellbeing of your pets. Although most fish tank owners purchase filters to help keep the water clean, even the very best versions on the market aren’t sufficient to keep your tank perfectly clean and healthy.

Here is our guide to everything you need to know about cleaning your fish tank.

How often do I need to clean my fish tank?

Exactly how often you need to clean your tank will depend on a number of factors including the size of your aquarium, and the number of fish, type of fish and the filter system that you have. However, there is a general schedule of cleaning activities that it would be beneficial to follow.


Daily: There should be no need to clean your tank daily, but there are some observations that you can make that will help you to understand if your tank is being cleaned often enough to keep your fish healthy. Just watch them for a few moments to make sure that they are behaving normally and aren’t gasping for air or seem sluggish. If they do then you may need to do another partial water change, regardless of how long it has been since the last one.


Weekly: If you have a particularly large tank then you may be able to get away with water changes slightly less often, but for most average-sized tanks, a weekly water change can be extremely beneficial to the health and wellbeing of your fish. To do this you should remove approximately one quarter of the volume of water in the tank, and replace it with treated water. You can use a scraper or sponge to clean off any decorative items that you have in the tank, and use your aquarium vacuum to give the gravel a good clean and remove any dirt and debris.


Monthly: It is important to keep an eye on the levels of ammonia, nitrate and pH levels within your tank and testing them once a month should be sufficient. Ideally they should be pretty steady from month to month, so keep a record somewhere safe so you have something to compare your readings to. Some indications of problems with the condition of your water can include cloudiness, a change in color, or if your fish are behaving abnormally. You should also clean your filter cartridges once a month.


Every 6 months: Twice per year you should complete a deep clean of your tank and all associated equipment. This means unplugging everything and checking it all out to make sure it is in good condition, including filters, pumps, lights and more. Make sure you replace anything that is broken or in poor condition, and use your tools to help remove dust, dirt and more.


What is the best way to clean my tank?

Here is our step by step guide to the best way to clean your tank.


  1. Unplug the heater and filter, and if you are using one, the air plug.

  2. If you have any artificial plants or decorations, remove these too.

  3. Start by cleaning the inside of the glass. There are many different tools that you can purchase to do this job, but a clean facecloth works just as well. Small, gentle, circular motions work best.

  4. Use a gravel siphon to remove around 25% of the water, putting it into a bucket for later disposal. The siphon has some suction and you can utilize this for sucking up any dirt or debris that is sat on the bottom of the tank.

  5. Gently scrub all of the ornamental features that usually reside in your tank, including any artificial plants.

  6. Give the filter pad a thorough rinse using cold, clean water.

  7. Replace the filter cartridge, ornaments and artificial plants back into your aquarium.

  8. Empty the bucket containing the ¼ tank of fish tank water into your bath. Then fill your bucket with tap water and using the thermometer, adjust the water temperature so that it matches that inside the tank.

  9. Add some water conditioner and aquarium salt as per the guidelines on your products. If your aquarium it less than 4 months old you should also add a living bacteria supplement too.

  10. Make sure that all of the salt is completely dissolved by stirring it thoroughly.

  11. Fill your aquarium back up slowly.

  12. If you have a power filter, fill it up with water now.

  13. Finally, plug the heater back in and arrange all of your artificial plants and ornaments in a way that pleases you. Don’t be tempted to put the lights on right away. By keeping it dark for a few hours after a water change and clean, you can reduce the impact of stress on your fish.