Having worked with fish most of my life, I have a strong desire to help others to be successful in the hobby.
How to Choose the Best Filter for a 10-Gallon Aquarium
What is the best filter for a 10-gallon aquarium? It depends on a number of factors:
- Size and species of fish being kept
- Number of fish
- Whether live plants are used or not
- The amount of time you have to maintain your aquarium
- . . . and many other factors
About 10-Gallon Tanks
Because 10-gallon aquariums are the most popular tank size, they are the most affordable if you want to have several tanks. These tanks don't provide the best environment for most fish because water quality and temperature can change rapidly.
To help give us the best possible water quality for these small tanks, we tried several different filtration systems. To keep costs down and prevent cross-contamination, we looked for options that could be used independently in each tank.
Types of Filtration
There are three basic types of filtration: mechanical, chemical, and biological. Some systems focus on one type of filtration; other types of filters utilize two or three methods.
Mechanical filtration refers to the process that removes solid particles from the water. This filtration method makes the water look better but does not remove dissolved wastes or harmful chemicals, such as ammonia or nitrites.
The most commonly used chemical filtration is the use of activated charcoal. This method absorbs dissolved organics from the water, helping to reduce harmful chemicals, odors, and color.
Biological filters take advantage of beneficial bacteria that break down ammonia and nitrite and convert it into less toxic nitrates.
In order to understand how biological filters work, it helps to understand how bacteria converts ammonia from fish waste into a much less harmful substance known as nitrate.
Understanding the Nitrogen Cycle
Types of Filters
There are many types of filtration systems you can use in an aquarium. Here are a few of the low-cost filtration systems we tried.
- Corner or box filter
- Undergravel filter
- Hang-on-the-back filter
- Multilayer corner filter
- Internal power filter
- Sponge filter
1. Corner or Box Filter
This was one of the first real biomechanical filters available to tropical fish hobbyists. This filtration system consisted of a layer of activated charcoal and some polyester fiber filter media. In this system, the activated charcoal provided chemical filtration of harmful ammonia and nitrites while the filter floss provided mechanical filtration and a location for beneficial bacteria to grow.
These filtration systems are still available; however, more effective systems have since been introduced.
2. Undergravel Filter
This filtration system was an excellent system when it was first introduced in the 1950s and became quite popular in the 1970s. Undergravel filters utilize a perforated plate that lines the bottom of the aquarium. A layer of gravel is placed above the filter. This gravel or substrate becomes the actual filter media in this filtration system.
The undergravel filter is powered by using air or a powerhead to draw water through the gravel and out a lift tube. This process helps bacteria colonize the gravel and provide good biological filtration. However, it does not provide good mechanical filtration and must be cleaned periodically using an aquarium vacuum to remove waste that accumulates within the gravel. Also, undergravel filters can become clogged by plant roots, making them less effective over time.
We found this filtration method to work well as long as it is properly maintained. To prevent the young fry from being trapped in the bottom of the filters, we made sure to have a good 2” of quality substrate on top of the filter. We chose plant varieties that did not produce massive root systems to help keep the plants from clogging up the undergravel filters.
While this filtration system still works, there are modern systems that are more effective and easier to maintain today.
3. Hang-on-the-Back Filter
These filters are designed to suck water through an intake tube into a filter system that hangs of the back or side of an aquarium. The water passes through a filter that is usually comprised of a filter bag that is filled with activated charcoal. This filtration method is very easy to clean as it only requires the changing of the filter media every couple of weeks.
We had some success with back filters. While these systems worked well, we did find that they would capture fry once in a while and would sometimes stop working after short power outages, requiring us to add more water to the filter until it started working again. We also did not care for the “waterfall” sounds that these filters created. One was fine, but dozens became quite noisy.
Another disadvantage of this type of filter system is that a large cutout must be made in the lid to provide room for the filter. This is a potential location for your fish to jump out of the tank.
There have been recent innovations in the design of back filters that eliminate some of these issues. One of the more affordable back filters that we really like is the Aqueon Quietflow Power Filter. This filter features a four-stage filtration system:
- Stage 1: Dense floss removes particles and debris.
- Stage 2: Activated carbon removes toxins, odors and discoloration.
- Stage 3: Patented Bio-Holster removes toxic ammonia and nitrites.
- Stage 4: Diffuser grid removes additional toxins while adding oxygen for more active fish. It also reduces splashing makes the return exceptionally quiet.
The pump has an internal pump design that helps keep the filter quiet and helps prevent leaks. This internal pump does not need to be primed, so it will start automatically after a power outage or after cleaning. This design is supposed to enhance water quality and clarity, increase oxygen levels, and lessen noise. A filter sponge can be added to the intake to prevent the filter from sucking up young fry, if you wish.
We have recently started using this very reasonably priced filter in combination with a sponge filter, and we have been very happy with the results.
4. Multi-Layer Corner Filter
These corner filters look similar to the old corner filters but with modern elements added to them. At the bottom of the filter are rocks and ceramic filter media. Layers of other filter media of different sizes are also added to the filter gradually, going to a fine filter at the top where the water enters the filter.
These filters looked like they would do very well, and we were excited to try them out. They were very affordable with a cost of under $10 per unit (not including the air pump). These filters are an excellent filter for tanks with shrimp or small fish like Endlers or guppies.
5. Internal Power Filter
We were surprised at how well this inexpensive filtration system worked. It is similar in design to a back filter, except this filter is completely submerged in the tank. These filters required a filter that is similar to the one used in a back filter to be changed periodically.
These produced a very small amount of water movement that seemed to work well with Endlers. Noise could be reduced by keeping the water level near the top of the filter.
6. Sponge Filter
Another very affordable filter is the sponge filter. These filters are driven by an air pump that helps drive water through the sponge media and back into the tank. They are relatively quiet because they have no moving parts; they only produce the sound of bubbles and the hum of the air pump.
These filters come in many different configurations, such as a corner variety or a round type. Our favorite sponge filter had two separate filters or heads. The two filters could be move to separate positions. These biomechanical filters provide mechanical filtration and a good environment for beneficial bacteria to help provide biological filtration.
We found these filters to be highly effective once bacteria had a chance to colonize the sponge media. When cleaning the sponges, we found it best to simply shake the filters in water that we had removed from the tank during a partial water change. This prevented the beneficial bacteria from being destroyed during the cleaning process. Our Red Cherry Shrimp seem to love to graze on the food particles that collect on the sponge.
The biggest disadvantage to the sponge filter is that they do not provide chemical filtration, and we found combining them with hang-on-the-back filters or internal power filters worked well in our Endler tanks.
Filtering Water Naturally Using Plants
Plants can be an extremely beneficial addition to an aquarium. Plants use some of the harmful chemicals such as nitrates and ammonia to aid in plant growth in an aquarium. This helps to stabilize the water conditions and can be beneficial in providing a better ecosystem for your fish.
While plants are very beneficial. they cannot do all the filtration for your fish especially if there are large numbers of fish in the tank.
So Which Filter Is Best?
Which is the best filtration system for you depends on your needs. Do you want high or low water flow? Do you want a system that is easy to maintain? How much are you willing to spend on your filtration system?
These are all things you will want to consider when choosing an aquarium filtration system. You may find that a combination of two types works best for you.
A Good Filter System Is Not Enough
A good filter system helps to keep the aquarium water clean and break down harmful fish waste. While this is essential for a good healthy environment for your fish, it is not enough to maintain a healthy environment.
To help prevent the buildup of harmful nitrites, ammonia and nitrates, the aquarium should have a partial water change periodically depending on the number and type of fish you keep and the type of filtration system used.
We do a partial water change approximately every 2-3 weeks. Removing approximately one third of the water and replacing it with fresh clean water helps to maintain a good environment while still leaving the beneficial bacteria in the aquarium.
Easy-to-Use Water Changer
Easily clean your gravel and refill your aquarium with an easy-to-use water changer (see video above). These specially designed water changers eliminate the need to carry buckets of water through your house.
Don't Like to Do Water Changes? Try a Drip System!
How would it be if you never had to do a water change for your aquarium ever again? It is possible if you use a drip system in combination with an overflow drain system.
Using this system you will need to make sure you have a water supply that is healthy for your fish. This would require good quality well water or water that has been filtered before it enters the tank.
The drip system uses ordinary drip emitters like the ones that are used in gardens and is quite affordable.
DIY Aquarium Overflow
Don't want to drill your tanks for your aquarium overflow? Here is a great method of creating an overflow for your tank without having to drill it out.
Cleaning Aquarium Gravel
Over time excess food, plant matter and fish waste can build up at the bottom of the tank. This is fed on by the beneficial bacteria that inhabit your aquarium. Too much of this waste can cause an excess of micro organisms to grow in your tank creating an unhealthy environment for your fish.
To help your aquarium stay healthy you should clean the gravel or bottom of your tank every week to two weeks. This cleaning should not be a complete cleaning as you don't want to completely destroy the beneficial bacteria that is living in your aquarium.
One of the most popular methods used to clean the gravel or bottom of tank is to use a gravel vacuum. With a gravel vacuum you can quickly clean your aquarium gravel or bottom of tank and do a partial water change at the same time.
My Own Aquariums: Raising Endlers in Small Tanks
One of my favorite and more profitable hobbies is raising Endlers. Endler's livebearers are a relatively new addition to the aquarium hobby. We started with only a handful of fish years ago and now have quite a large number of fish, relatively speaking, at MartysFish.com. These highly active and beautiful livebearers are easy to care for and are a real pleasure to watch.
Because we have several different strains—both pure strains and hybrids—we must keep the majority of our Endlers in small 10-gallon tanks to help control genetics and maintain a wide variety of fish in a very limited space. For each strain we raise, we need a minimum of eight tanks in order to keep proper control over breeding and ages.
Aquarium Water Quality for Our Endlers
One of the most important aspects in keeping Endlers healthy is to provide them with a stable environment with good water quality. Because we use such small tanks, it is very important that we have a good filtration system to keep the water quality as stable as possible.
Our Experiments With Filters
We have spent years experimenting with different types of filters and tank set-ups to try to find the ideal filtration system for our situation. It was important to us to minimize cost as much as possible as well as have a system that is portable because we move fairly often. Because Endlers are fairly small fish that don't care for extreme water movement, we had to make sure that the filtration system wasn't too strong for the small fish.
The Tanks We've Used: Nano Reef Tanks
We were fortunate enough to find an “AquaPod” 12-gallon aquarium several years ago at a local thrift shop. This all-in-one is most often used for those wanting a small saltwater aquarium or reef tank. It has a wonderful filtration system built into the back of the tank which also has a skimmer to help remove buildup on the water surface.
We added about 2” of dark substrate made by Fluval to the bottom of the tank. This made a nice base for a variety of plants that we added which grew well in the tank. The plants, lighting and filtration system created an ideal environment for our Endlers, and we had hundreds of them in a few short months. Unfortunately, there was a safety recall for that particular tank so we were not able to get anymore.
There are, however, other brands such as the 14-Gallon Oceanic Bio Cube which have a similar design. While this type of aquarium system works very well, they are quite expensive if you want to keep a large number of tanks. We found that we did get a little bit more algae in this tank than some of the others however we found that the fish stayed quite healthy and it is an excellent breeding tank for our special Endlers.
How to Maintain a Healthy Aquarium
Maintaining a healthy aquarium is not very difficult. Here are some things that will help keep your water clean and your fish happy:
- Cycle tank before stocking it with fish.
- Do not over stock your aquarium.
- Do not overfeed your fish; several small feedings are usually much better than one large feeding.
- Use the appropriate filter system for your type and number of fish.
- Do periodic partial water changes.
- Never completely empty and clean your tank unless absolutely necessary. This will kill the beneficial bacteria that you worked to colonize your aquarium. Complete water changes can be very stressful for your fish and can leave your fish susceptible to illness.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
Marty Andersen (author) from Salina, Utah on March 11, 2015:
That looks like a great filter design. Too bad I won't get a chance to try it out.
alphajuno from League City, TX on March 11, 2015:
I like the Marineland Duetto 50 Submersible Power Filter but it looks like it was recently discontinued. It has a soft flow which is good for small fish.