How to Maintain a Healthy Home Aquarium

February 23, 2024 Cermedia

How to Maintain a Healthy Home Aquarium

An aquarium can be a beautiful and rewarding addition to your home—there’s a reason that 12% of American households keep fish! As home aquarists know, there are few things more relaxing than watching your fish explore the world you’ve built for them.

So how can you be sure that you’re maintaining a suitable environment for your home aquarium to thrive? Tank maintenance can seem overwhelming, but it’s really quite simple as long as you have some basic knowledge, and a good routine. By consistently following your aquarium maintenance regimen, you’ll spend less time maintaining your tank, and more time enjoying it.

Getting started right by cycling your tank

If you’re just setting up a new tank, you’ll need to take some time to cycle your fish tank. Cycling is an important step that establishes beneficial bacteria in your tank. These bacteria are crucial for breaking down harmful ammonia that comes from fish waste, decaying plants, and uneaten food. With a properly cycled tank, beneficial bacteria act as a microscopic waste management team that drives the nitrogen cycle, a multi-step process where toxic ammonia is converted into comparatively less toxic nitrites, nitrates, and in some cases, nitrogen gas.

Cycling can be achieved either with or without fish. When using fish to cycle a new tank, the tank is purposefully understocked with hardy fish species. As the fish produce waste, ammonia levels will rise and feed a growing population of beneficial bacteria. However, this can be stressful for even the hardiest fish. For this reason, many people prefer fishless cycling as a more humane method. To cycle a tank without fish, you’ll need to provide a source of ammonia to the tank until bacterial colonies are established. Popular methods for fishless cycling include adding small amounts of pure ammonia to the tank every few days, or leaving food in the tank to naturally release ammonia as it decays.  

Depending upon the size of the tank, the cycling process may take anywhere from a couple of weeks to a couple of months. During this time, you’ll need to test for ammonia and nitrite levels. Once the tank is cycled, ammonia and nitrite levels should be zero, and nitrates should be around 20-30 parts per million (ppm). At this point, you’re safe to add fish, and move to a regular maintenance routine.

Cleaning the tank

Over time, uneaten food, fecal waste, dead plant matter, and other debris will settle on surfaces within your tank. Not only does this debris make your tank less visually appealing, but it can also lead to higher levels of ammonia as it breaks down. That’s why you should clean your tank at least once per month, or up to weekly if you keep a lot of fish or if your fish produce a lot of waste.

Your routine cleaning will include a few steps:

  1. Prepare: Start by turning off the filter and heater, and gathering tools such as an algae scraper, bucket, and gravel vacuum.
  2. Clean the tank: Next, scrub or scrape the inside walls to remove excess algae or other buildup. Using a magnetic scraper or long-handled scrubber will make cleaning quick and easy. You may also want to shake plants to dislodge any debris, and clean decorations as well. When cleaning, remember that algae is a sign of healthy tank, and it is also a food source for some species, so it can be beneficial to leave some behind.  
  3. Clean the substrate: Next, you’ll need a bucket and a gravel vacuum to loosen and remove debris from the substrate. The gravel vacuum should be slowly passed over the gravel in rows as it siphons water from the tank into the bucket. You should stop vacuuming when you’ve removed about 25% of the water.
  4. Clean the filter media: The last option is to clean your filter media. Often, this is achieved by gently rinsing filter media in the bucket of water you’ve just removed from the tank. The goal is to remove any solid debris without washing away too much of the beneficial bacteria that have grown on the filter media. Always follow manufacturer recommendations for maintenance and replacement. If you’d like to minimize maintenance demands, consider switching to high-end filter media that resists clogging and can be used for years without replacement.
  5. Finish up: Lastly, you’ll need to replace the water you’ve removed (see Water Changes), reassemble your filter, and turn both it and the water heater back on. If the outer glass is dirty, you can also clean it with vinegar or another aquarium-safe cleaner.

Changing aquarium water

A natural aquatic ecosystem is constantly refreshed by currents that bring in fresh water. But because your tank is a closed system, it needs some help to bring in fresh minerals and remove nitrates produced by the nitrogen cycle. To maintain your tank, you should do a partial water change somewhere between once per week and once per month, keeping in mind that lower fish loads will usually mean you can get by with less frequent water changes. You may also be able to increase the time between water changes by using high-end filtration media that can help keep nitrate levels lower by housing microbes that convert nitrates to innocuous nitrogen gas.

How to do a water change

To do a water change, first remove about 25-30% of the tank water with a siphon, and then refill the tank with properly conditioned water. It makes sense to do a water change after your normal cleaning routine since you’ll be removing water when you vacuum the gravel.

When refilling, make sure that the new water is suitable for use in your tank. Since chlorine is toxic to fish, aquatic plants, and beneficial bacteria, you should test any water that you plan to use in your aquarium, and use a water conditioner if needed to remove chlorine and/or chloramines. The replacement water should also be similar in pH, hardness, and temperature to the tank water so that it does not upset the tank biome.

Testing water parameters

Sometimes, even with proper maintenance, problems can arise in your tank with seemingly no warning. To stay ahead of any issues that may be brewing, you should test freshwater tanks at least once per month, and test saltwater tanks or freshly cycled tanks weekly. Aquarium testing kits  provide the tools needed to test for various water quality parameters, including:


While a natural part of the nitrogen cycle, ammonia is extremely toxic to fish. Even at low levels, ammonia will burn your fish’s gills, interfere with their ability to take in oxygen, and even cause internal organ damage or death. That’s why ammonia levels should be kept to 0 ppm.

Ammonia is contributed to the tank by fish urine and feces, and through the decay of dead plant matter and food. If your tests indicate elevated ammonia levels, you’ll need to identify the cause, and try to correct it. Ammonia spikes are often caused by:

  • Overfeeding: Uneaten food will break down and release ammonia. To solve this problem, try to reduce the amount of food or the frequency of feedings, and/or clean the tank more often to remove uneaten food.
  • Overstocking the tank: The more fish in the tank, the faster their waste will accumulate. Addressing this issue may mean you need a bigger tank, more frequent cleaning, and/or higher biological filtration capacity.
  • Too little surface area: Beneficial bacteria will colonize any surface in your tank, so providing as much surface area as possible will ensure that their population is large enough to keep up with all the waste being produced in the tank. Consider upgrading your biological filtration media to increase useable surface area.
  • Excessive cleaning: If you clean your filtration media too vigorously, you risk losing the beneficial bacteria that help to break down ammonia. Gently rinsing your media in tank water is usually enough to remove debris while still preserving bacteria. Additionally, when replacing your filter media, it is often beneficial to retain a piece of the old media to help “seed” the new media with beneficial bacteria.  
  • Chlorine in replacement water: A spike in ammonia following a water change may suggest the presence of chlorine in your replacement water. Since chlorine can kill off beneficial bacteria, you should test your replacement water and condition as needed to remove chlorine.

When your tests show ammonia, it’s always best to identify the source of the problem and address it directly. But if ammonia levels are particularly high, there are some emergency actions you can take to protect your fish, like using an ammonia remover product, or doing a water change with a higher percentage of your tank’s water (50-75%).  

Nitrites (NO2)

During the second phase of the nitrogen cycle, Nitrosomonas bacteria break ammonia down into nitrite. While somewhat less dangerous than ammonia, nitrite is still quite toxic to fish, as it prevents them from absorbing oxygen into their bloodstream. For this reason, nitrite levels should measure 0 ppm. If your test indicates excess nitrites, it is likely that your tank is also having problems with ammonia spikes. Consider doing a water change and be sure to investigate any underlying causes of excess ammonia.  

Nitrates (NO3)

During the final phase of the nitrogen cycle, Nitrobacter bacteria convert nitrite into nitrate, a compound that is far less toxic to fish than either nitrite or ammonia but can still cause issues. Nitrate levels should be kept below 40 ppm for freshwater tanks, while saltwater tanks should have nitrate levels below 10 ppm. These guidelines can vary depending upon the fish, though, so be sure to research the needs of fish species you plan to keep.

Nitrates are typically diluted through routine water changes, so if nitrate levels exceed the recommended limits, it may be necessary to do water changes more frequently. Nitrates can also be present in tap water, so be sure to test your replacement water to ensure you’re not introducing nitrates during your water changes.   

Aquarium plants, algae, and certain anaerobic bacteria can also be useful in keeping nitrate levels down since they consume nitrates as a source of food. Leaving some algae behind after cleaning can be a simple and effective strategy, as can adding more live plants to the tank. Additionally, some types of biofiltration media provide low-oxygen areas that house bacteria capable of converting nitrates to nitrogen gas. These nitrate management strategies can help reduce the frequency of water changes and promote a more consistent environment in your tank.    


If the water in your tank is either too acidic or too alkaline, your fish can become stressed, diseased, or even die. It’s always best to know the specific pH range for the species you keep, but for most fish, you should aim to keep a neutral pH between 6.5 and 7.5.  Some fluctuation in pH is normal due to plant and algal growth cycles, or due to cyclical accumulation and breakdown of wastes. If testing consistently lands outside the acceptable range, though, you may need to take action to adjust the pH. Just be aware that fish are sensitive to drastic changes in pH, so exercise caution if you plan to use a commercial pH adjustment product, and consider alternative pH adjustment methods, as these can be slower and therefore safer for fish.

Biofiltration and tank maintenance

Maintaining a healthy tank is all about creating a balanced ecosystem. Beneficial bacteria are the very foundation of that ecosystem, working constantly to manage wastes produced by the aquatic life in your tank, and keeping toxins in check between cleanings and water changes. Maximizing the population of bacteria will go a long way toward improving the stability and overall health of your tank.

That’s where biofiltration comes in. By providing lots of surface area, biofilter media provides a place for all that beneficial bacteria to live.

How can MarinePure® help?

MarinePure® biofilter media provides an exceptionally large amount of surface area for beneficial bacteria to grow, and a unique continuous pore structure that allows water to flow through the media with ease. MarinePure’s® unique ceramic structure also provides low-oxygen zones to house bacteria that convert nitrates to nitrogen gas. These features allow MarinePure® to outperform many other types of biofilter media by facilitating quicker and more complete nitrification and denitrification. As a result, MarinePure® will allow you to do fewer water changes, and reduce the overall maintenance demands of your tank.

MarinePure® is also available in a variety of shapes and sizes to suit nearly any biofiltration application. If you’re interested in trying MarinePure® in your aquarium, just click on over to our website to find a retailer, or reach out to us. We’d love to help walk you through how to use MarinePure® for a cleaner, easier-to-manage fish tank.

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Contact us to learn more about how MarinePure and BioVast can help your aquarium and aquaculture environments!


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