Healthy Ways to Keep Fish Tank Clean Without Changing Water

How many times have you heard, “I change the water in my tank and my fish die.”? Well, you tried everything and your fish is still dead? This article has some useful rules to follow in order to keep your fish tank clean while barely popping open the cover.

So, how do you keep your fish tank clean without changing the water?

Short answer: The best thing you can do for your aquarium fish is to supply them with clean water on a regular basis, there is no shortcut to it.

healthy ways for fish

Why clean water for a fish tank?

  • Dirty water tanks serve as a breeding ground for harmful bacteria:

Bacterial diseases can be a major cause of death in aquarium fish. There are members of at least 25 genera of bacteria that have been considered as possible causative agents of bacterial diseases in fish.

Disease-causing bacteria in fish are usually found around the fish, in the surrounding water, on the surface of the fish, or in their internal organs.

Bacterial infections manifest in many ways, but common signs include a white film on the fish’s body or fins, cloudy eyes, tattered fins, and bleeding (bloodstains) or open sores (ulcers) on the body and mouth. If you still see white spots on your fish even after 5 days or more of firsthand treatment, your fish may have a secondary bacterial infection where parasites burrow into their bodies.

Treating bacterial infections can be difficult and should be done with caution as some antibiotics can interfere with your aquarium’s biological filter. Also, unless you have access to an incubator and are unfamiliar with fish pathology, it is next to impossible to correctly diagnose which specific bacteria have infected your fish.

However, there are some trends and some medications are known to be effective in certain cases. Always consult an experienced aquarist before treating your fish for bacterial infections.

Understanding what your fish looks like and “normal” behavior is helpful in identifying problems that may arise. Watch your fish regularly – feeding time is a good opportunity to do this. Look for white spots, cloudy eyes, bloodstains, a white film on the body, or torn and frayed fins. There are also some things that fish never do (or at least very rarely).

  • Reduction of harmful compounds

Toxic aquarium water can lead to fish poisoning if left untreated for long periods of time and can lead to fish disease and even death.

Toxic substances can enter the fish through the gills, which allows them to act rapidly and weaken the animal. This causes the fish to become vulnerable to disease.

Ammonia poisoning

Ammonia poisoning is a common cause of fish death. It can be caused by a variety of factors, such as a change in the bio-load or a power outage.

The signs of a fish that is dying are usually: motionless, red gills, and a lack of appetite. These symptoms are preceded by bleeding gills and internal bleeding.

Nitrite Poisoning

Although nitrate is less toxic than ammonia, it still has a toxic effect on the fish and can cause long-term health issues.

Nitrite enters the bloodstream of a fish and prevents its oxygen-carrying cells from working properly. This causes it to suffocate the fish. It’s the same as ammonia poisoning.

CO2 Poisoning

High levels of CO2 can kill fish. Symptoms of CO2 poisoning include sudden breathing difficulties, rapid heartbeats, and staggering swimming behavior.

If the lights are not working properly, or the CO2 reactor malfunctions, then the plant will not be able to absorb the CO2. This can be solved by agitating the tank and air-stones.

  • Replenishing Essential Minerals and Trace Elements

Due to the nature of our environment and the size of our aquariums, trace elements can be depleted rapidly. This is especially true for trace elements that are very small.

Trace elements are important to the success of various biological processes in our aquariums. However, they should not be added too much or too little to avoid potential issues.

Maintaining Water Quality

water quality

Over the years, various improvements have been made to make maintaining a healthy aquarium easier. However, despite these changes, maintaining a good water quality can still be challenging.

1. Proper aquarium setup

Most new fish tanks are built with the proper materials and are not contaminated with toxic chemicals. However, they can still cause problems if they are not cleaned regularly.

Setting up the aquarium with a clean substrate, wood, and rock for aquarium use is the first step in maintaining water quality.

2. Testing of Aquarium water

Knowing the correct level of ammonia, nitrate, nitrite, and pH in your water is very important for successful aquarium setups. A good quality tank with plenty of nutrients is also important to maintain a healthy environment. Therefore, weekly monitoring of all the water quality parameters is essential before the tank becomes stable

If your tap water is very hard and has a pH of 8 and above or is very soft and acidic with a pH of 6 or less, you have two options. You can constantly condition and adjust the water during the weekly water change, or you can choose fish species that suit your water conditions. Choosing the right type of fish will make water maintenance much easier.

3. Changing water

Weekly water changes are probably the most important part of maintaining good water quality. Weekly water changes of around 15-20% of the total water volume will solve many potential water quality problems. The water change brings water rich in minerals into the tank. By removing the water, you also reduce the number of nitrates that accumulate in the water. Weekly water changes also help remove other toxins or pollutants that can build up in the tank.

4. The use of Live Plants

Whether or not live plants live in an aquarium is often a personal decision and many aquariums get along very well without ever having a live plant in them. However, live plants in an aquarium offer several benefits.

Plants are excellent at absorbing carbon dioxide and nitrates and offer protection and safety to fish. As they compete with algae for nutrients, they can also help reduce algae growth. Live plants also improve tank appearance and provide a much more natural environment for fish.

Sterilizing fish tank and equipment



Depending on the reason for the tank sterilization, one of two methods can be used. If you want to thoroughly clean a dirty tank, vinegar and water are a quick and effective solution. However, if the aquarium had any diseased fish, you will need to use a stronger solution such as bleach.

  1. Cleaning fish tank and equipment with Vinegar

Vinegar can be used to clean the tank, filter, heater, and all decorations with a 1: 1 solution of vinegar/water. All items can soak for several hours. When the items have finished soaking, rinse everything thoroughly. Your aquarium and equipment are now ready for use. When the tank is full of water, be sure to use a good water conditioner.

If hard water has accumulated on the filter, you can let it run in a bucket with a water-vinegar solution for a few hours. This cleans the entire interior and breaks down hard water. If a stronger solution is needed, use a 2: 1 ratio of vinegar to the water. Rinse thoroughly before returning it to the aquarium.

Note: This is one of the most favorable ways to sanitize fish tanks without bleach.

  1. Bleach solution.

The bleach must be ordinary household bleach. Do not use bleach mixed with other detergents. The solution is usually eight parts of water to one part of bleach.

There are two ways to use bleach in your aquarium.

  1. Put the bleach in a spray bottle and spray the inside of the aquarium. Let it sit for 10-15 minutes before rinsing thoroughly. Don’t leave the bleach more than this specified timeframe. Bleach is caustic and can damage the aquarium. The tank should air dry for 24 hours before use.
  2. Use an 8: 1 water/bleach ratio to fill the aquarium. Leave to rest for 10-15 minutes and nothing more. Rinse the tank thoroughly and allow it to air dry for 24 hours.

After allowing the tank to dry for 24 hours, fill it with water and add a dechlorinator. Let it sit for an hour or two.

Empty the tank and refill it with water and the tank is ready for use.

Decorations, filters, and heaters can also be cleaned with the same water/bleach ratio of 8: 1. You can dip them or spray them. The same rule applies to tanks. Do not leave anything with bleach for more than 10-15 minutes. When you’re done, rinse everything thoroughly. Remember to let everything air dry for 24 hours before putting it back in the tank.

Steps to changing aquarium water

A clean aquarium not only looks good, but it also helps keep the fish healthy and happy. This is because nitrates and metabolites can build up over time which can affect the appearance of your aquarium and the well-being of your pets.

Materials Neededclean

  • Bleach
  • Clean towel
  • Clean water
  • Dechlorinator
  • Filter media
  • Fish container/Bucket/Bowl
  • Pad/Algae scrapper
  • Scoop net
  • Siphon



  1. Unplugging of all electrical items and water removal

Use a siphon vacuum cleaner with a hose attached to clean gravel and remove water.

With the siphon you should suck up small amounts of gravel, the waste is then sucked along with some of the water through the hose into the bucket and the gravel falls back.

Block the end of the tube with your thumb to slow down the suction process and make sure that gravel does not enter the tube.

Some siphons have a built-in regulator to control the flow of water, while others also have longer hoses to allow water to go directly into the sink (when not needed to rinse other appliances).

  1. Cleaning the inside of the aquarium

The inside of the glass must be regularly scraped from algae stains and protein deposits. The best time is during a regular water change to ensure that as much debris is removed.

Always use a clean scraper to clean the glass. Never use a cleaning pad that has come into contact with soap.

If you use a swab or tool that allows your hand to come into contact with water when cleaning the aquarium glass, be sure to rinse your hands and arms. You should remove any lotions or other creams that might otherwise enter the system. The less pollution you add, the better.

Various tools are available for cleaning the aquarium glass: razor blade scraper, plastic blade scraper, sponge on a stick, cleaning swab, algae magnet, example with acrylic tanks you need to use a soft cleaning pad to prevent scratches.

Algae magnets are best for people who frequently clean glass so that hard debris never gets a chance. However, the cleanability of the aquarium glass is directly a result of the strength of the magnets. Make sure you purchase a magnet designed for the thickness of the aquarium glass.

  1. Substrate maintenance and gravel cleaning

Cleaning the aquarium gravel is very important for the well-being of the fish, as a lot of dirt sticks in the gravel. The main tool for removing solid dirts is the gravel cleaner.

The gravel cleaner is primarily a siphon tube connected to a rigid tube. As soon as the siphon started, usually with a few movements of the hand to slide it, the rigid end of the tube is driven into the gravel subsoil.

The rigid siphon pipe is usually routed through the gravel layer in a regular pattern. The siphon flow sucks dirt and debris up and out with the water jet.

The ideal flow is such that the gravel particles are partially pulled up into the rigid pipe and then fall back to the bottom. The dirt hidden in the gravel is pulled up from the stream and disposed of in the bucket.

The water removed is the dirtiest in the aquarium. In most cases, so much dirt is removed that the water becomes almost peach black.

  1. Cleaning of Filter

Depending on the type and quality of the filter used, you will need to clean the medium in the water filter and sometimes change it.

The most common type of filter is a sponge filter. To clean it, you should take it out and rinse it in the bucket of water you took from the tank.

Never put the filter under tap water as it will remove the beneficial bacteria that have built up and which are necessary for your aquarium.

All other filters that act as a mechanical filter such as a sponge (ceramic rings, filter fibers, etc.) must also be rinsed and returned as soon as possible to avoid losing bacterial colonies.

You should also clean the rest of the filter including the pipes; Use a filter brush to do this.

  1. Refiling the tank with dechlorinated water

You need to prepare new water to fill the tank. You will need a clean bucket to prepare water for the change. Make sure the last water you add to your aquarium is safe and free of living things.

De-chlorinated tap water or deionized water (RO / DI water) can be used.

If using tap water, make sure it is treated with a conditioner / de-chlorinator to remove chlorine or chloramine.

Freshwater treatment/preparation

If you can, it is advisable to prepare the water ahead of time, and let the tap water sit for 24 hours before cleaning the tank to allow the chlorine to evaporate naturally.

It is necessary to use a water purifier to remove heavy metals, chlorine, and toxins that are harmful to fish.

By preparing the water in advance, the water can even reach room temperature.

Saltwater treatment/preparation

When changing the water in saltwater tanks, you need to be more specific. You need to be aware of three parameters: salinity, temperature, and pH.

For reef aquariums, RO / DI water (reverse osmosis and/or deionized water) is required. You can purchase it from your local fish shop.

You should only use tap water if your local supply is excellent, and even then, tap water should only be used for pure fish aquariums. If you have to use tap water, have it tested for TDS (Total Dissolved Solids). This reading should be zero, but anything below 10 is fine.

It is necessary to de-chlorinate the water and then add a salt mixture. There are many different options, so make sure you choose a high-quality, trustworthy brand. Follow the instructions for the product you have chosen.

You should let the water sit overnight before adding it to the aquarium so that the salt can dissolve completely.


We hope you find these tips helpful. Following a few hints can make your life much easier and also the life of your pets.

We would love to have your thoughts in the comments.

Best Fishes.

Recommended Reading: When Should I Feed My Fish For the First Time?

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