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How Often Do People Clean a Freshwater Fish Tank? Answered

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Cleaning your freshwater fish tank is crucial to keeping ammonia, nitrates, waste, and other toxic elements to a minimum. Frequent cleanings allow you a more visually appealing tank and healthier fish. 

Freshwater tanks should be cleaned once every two weeks. This depends on the size of your fish tank and how many fish are housed in the tank. If you have a smaller tank that is overpopulated, cleaning the tank once a week is recommended. Full tank cleanings are recommended twice per year. 

Keeping your aquarium clean can be a hassle, but it is essential for a healthy environment for your fish and live plants. With a cleaning schedule and knowledge of the topic, you will have an easier time handling the chore. 

Choosing Between Weekly, Bi-weekly, or Monthly Cleanings

When trying to decipher how often you should clean your freshwater fish tank, it is essential to consider all of the different factors. These include what type of filtration system you have, how many fish you have, how much waste you can see in the tank, and how large, or small the tank is. 

Weekly Cleanings

Weekly cleanings are recommended when you have a small tank with multiple fish, such as a five or ten-gallon. Remember when we say weekly cleanings, we are not talking about a deep clean (we’ll cover this later).

If you notice algae growing on the walls of your tank, excessive fish waste, brown spots on live plants, or your fish avoiding the bottom of the tank; your tank needs to be cleaned.

To start, you can use an algae scraper to get any visible algae on the glass of your aquarium. The next step would be to use a gravel cleaner to remove any visible excess waste at the bottom of the tank. 

When completing a weekly cleaning, it is also important to remember to check if the filtration systems are working and to ensure the filters are not clogged. If the filter is too dirty, it should be replaced. Remember never to rinse off filters with tap water; this can cause harm to your fish! Also, check any tank air stones to ensure they are not clogged.

Once these steps have been completed, you can start a partial water change. A partial water change entails taking a certain percentage of water out of the aquarium and replacing it with clean, unchlorinated water. 

Close up of hands adding water to fill freshwater aquarium. Fish tank maintenance.

For a smaller tank with a lot of fish, you should replace about a quarter to half of the water every week to remove contaminants. This would not necessarily need to be done weekly for a larger tank because there is more water to work with. 

When doing any cleanings, it is also a good habit to check your tank parameters with a testing kit. 

Bi-weekly Cleanings

Similar to weekly cleanings, bi-weekly cleanings are completed every other week. This is a great option if you have a larger tank such as a 20-55 gallon. If you find that after a week, you have little waste in your tank, you can wait an extra week to clean your tank.

Again this is common for larger tanks, tanks with an impeccable filtration system, tanks with fewer fish, or tanks that have more bottom-feeder fish that get the job done for them!

You would essentially follow all of the steps above for a weekly clean. Remember to again check any filtration systems, air pumps, and heaters to ensure they are working properly. 

Monthly Cleanings

If you have a large tank, 75-100 gallons or more, monthly cleanings may be suitable; particularly if you only house a few large fish in said tank. If the water remains clean for the month and the parameters stay in range; monthly cleanings will suffice!

Again, you would complete all cleaning steps as you would for weekly and bi-weekly cleanings. Check filtration systems and rinse the  filters with water, not tap water) from the existing tank (ensure the biomes stay beneficial). 

Care for the aquarium filter in a freshwater aquarium. Cleaning and rinsing

During a monthly cleaning, you should also make sure all chemicals that are used have not expired and stock up on any materials you may need. This includes but is not limited to a de-chlorinator, an algae controller, fish food, filters, and any medicinal chemicals you may need.

Semi-Annual Cleanings

Regardless of the above cleaning routine that works better for you, a semi-annual cleaning should always be done on any home aquarium. A semi-annual cleaning includes everything a basic cleaning does, but is a bit more in-depth.

For instance, you will want to unplug all components such as filters, bubblers, heaters, and lids and do a heavy shrub on them. Do not use chemicals. A scrub brush and water from the tank are recommended. 

However, if there is debris on the top of the lid (food or scum for evaporated water) you can use a touch of vinegar and hot water. Ensure you do not do this while the lid is on the tank and that the lid is rinsed off properly. 

You should also verify that all of the mechanics of the tank are working correctly as well, and replace parts if necessary. 

Deep Cleanings 

Deep cleanings should only be done in a tank if you have a disease outbreak that is not curable by any medicines or solutions. A deep clean includes removing all fish from the tank, removing all water from the tank, and removing all decorations, plants, and gravel. 

Again, this should only be used as a last resort. A deep clean will disrupt the cycle of the tank and stress out your fish, which could cause death. 

If a deep clean is necessary, remember that the tank must cycle before adding your fish back into the tank. Also, make sure to check the parameters of the water before adding your fish back in. 

Partial Water Changes

As mentioned, a partial water change is recommended when doing cleanings, whether it be weekly, or monthly. Doing a partial water change will remove some of the waste in the tank without adding too much stress to your fish (you can keep them in the tank while cleaning).

Depending on the size and amount of waste in the tank, you can take out a different percentage of the water while remaining safe for the fish. If you notice that the water is green and fish are swimming to the top of the tank for oxygen, you can take out 75% of the water. Always leave at least 25% of the original water in the tank. 

If you have a large tank that is mostly clean, you can change out 25% of the tank bi-weekly. However, if you have a small tank that is spotless, you would be safe to only take out about 10% of the water. Use your judgment depending on the cleanliness of the tank. 

Tools Needed for Freshwater Aquarium Cleaning 

Cleaning your aquarium can be a hassle, but having a few tools ready will make it much more manageable. You will need a siphon to remove water from the tank, a bucket to dump out the water, a fish net (which can be used to remove waste), an algae scraper, filters, and a chlorine remover. Paper towels should also be handy. While not used in the tank, water is bound to get on the floor! 

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