One of the most important habitat considerations when setting up your turtle tank is the filtration system. As anyone who has ever had a turtle can attest, turtles have extremely high bioloads. They are messy eaters, and they eat and take care of their business underwater. As a result, turtle tanks require a strong filtration system to handle the large amount of organic waste produced.
In this article, I will help you understand the things to consider when choosing your filtration system, and will introduce you to some of the best filters on the market.
When choosing a filtration system for your turtle tank, it is important to consider two key features: the type of filtration you will need and the type of filter you want to use.
Types of Filtration
Aquatic filters can perform three types of filtration: mechanical, biological, and chemical:
1. Mechanical Filtration
Mechanical filtration refers to the physical act of removing organic particulates from the tank, including food scraps, feces, algae, and debris. It is usually completed using a sponge, aquarium filter floss, or some other media that is able to trap the particulates as the water flows through it.
Mechanical filtration is essential to deal with the high bioload of your turtle. It helps keep the tank looking clean and clear, but does not influence the water chemistry.
2. Biological Filtration
As the name suggests, biological filtration is completed by “good” bacteria that live in a substrate within the filter. The bacteria can be located in the mechanical filtration media, or in a separate substrate within the filter.
Turtle feces releases ammonia into the tank, which in turn alters water chemistry. Ammonia is harmful to turtles, and if present in high enough concentrations, it can be deadly. The “good bacteria” in the biological filtration system, also known as ammonia oxidizers, convert the ammonia into less harmful nitrates, which can be removed from the water by aquatic plants or via periodic water changes.
3. Chemical Filtration
Chemical filtration further stabilizes the water chemistry in your tank by collecting additional harmful chemicals. The two most common types of chemical filtration are activated carbon filtration and ammonia removers. Activated carbon breaks down dissolved organic matter, while ammonia removers break down any ammonia not addressed by the biological filtration.
Some filters only perform one or two of these types of filtration. When choosing a filter for your turtle tank, it is important to confirm that it performs both biological and mechanical filtration. Chemical filtration is beneficial for the maintenance of the tank, but not essential for the health of your turtle.
Types of Filters for Turtle Tanks
When choosing a filtration system, it is important to remember that most filters are classified with fish in mind. Therefore, when looking at the recommended tank size for your filters, you want to choose a filter that is recommended for a tank 2-3 times the size of your turtle tank.
There are four main types of filters:
1. Canister Filters
Canister filters are external units that are typically placed adjacent to the tank. They are the best option for most turtle tanks, as they have the strongest filtration power.
However, they also tend to be more expensive than the other types of filters and are typically more time consuming to maintain.
2. Submersible Filter
Submersible filters sit on the side or bottom of the tank. They are typically the best for tank aesthetics, though not always the strongest filter.
Submersible filters are best for starter tanks with small turtles where the bioload is smaller. However, as discussed below, there are a few submersible filters on the market that can be used in larger turtle tanks.
3. Hang-on-Tank Filter
Hanging filters are the most common aquarium filters for fish-focused aquariums. However, they are not typically recommended for turtle habitats because the water level in the tank must be high for the filter to be effective.
As we discuss in A Beginner’s Guide to Setting up the Ideal Turtle Habitat, turtles require a basking area. With a basking area at the top of your tank, it is typically impossible to keep your water level high enough to work with the hanging filtration system.
That being said, if you have a setup that allows for the hanging filtration system, such as an external basking area setup, these filters are also powerful enough to keep up with a turtle bioload.
4. Under-Gravel Filter
Under-gravel filters are frequently used for fish-focused aquariums. However, they should not be used in turtle tanks. Turtles enjoy digging, which can lead to broken, clogged or disconnected filters. Their digging can also dislodge the good bacteria and organic particulates in the filter media, which in turn renders the mechanical and biological filtration of the filter less efficient.
Best Canister Filters for Turtle Tanks
1. Penn Plax Cascade Canister Filter
The Penn Plax Cascade Canister filter is a fantastic filtration option if you have a large turtle or a large turtle tank. With a maximum flow rate of 350 gallons per hour (gph), the Penn Plax Cascade Canister Filter has one of the highest capacities we’ve seen on the market.
The Penn Plax Cascade comes in a variety of sizes, ranging from 30 gallons to 200 gallons. It is a compact filter with input and output piping that rotates 360o, making it perfect for storing in tight spaces next to or behind your tank.
One of the best features of the Penn Plax Cascade is its media trays. The Penn Plax Cascade comes with three large media trays that can be loaded with any media you desire. This means that you can choose the type of mechanical, biological, or chemical filtration you want in your tank at any given time.
While these customizable media trays are great for intermediate to expert aquarists, they can be a bit overwhelming for anyone just starting off. However, don’t let that dissuade you. You can buy filtration media that is ready for use in pet stores or online.
If you do not plan to customize your filtration media right away, just make sure you purchase filtration media when you purchase the filter, as the filter does not come with filtration media.
The largest downside of the Penn Plax Cascade is that it makes noise. Therefore, if your tank is in a bedroom or another room where the sound of the motor will be distracting, this filter may not be the best one for you.
2. Fluval Canister Filter
The larger your turtle and turtle tank are, the more you are going to want to invest in a heavy-duty, reliable filtration system. Though Fluval Canister Filters are by far the most expensive filters on the list, they are also unmatched in terms of power and capacity.
If you have a tank that is 100 gallons or larger, you cannot beat the Fluval Canister.
The Fluval Canister Filter is one of the only filters that feels like it was designed with your turtle tank in mind. It comes in a variety of sizes and strengths, with the largest topping off at a 400-gallon capacity and a flow rate of 560 gph.
The Fluval Canister Filter has media trays that pull out vertically, making them durable and easy to use. The media trays can be filled with several different media options designed by Fluval, so you can customize them based on your tank requirements.
Unlike the other filters on this list, Fluval Canister Filters come with two unique features. The first is the purge valve at the bottom of the canister, which can be used to release the water in the canister prior to maintenance.
The second is the Fluval Canister Filter’s smart pump technology. Fluval Canister Filter pumps turn off briefly once every 12-24 hours to allow any air bubbles in the system to dissipate. This ensures that your filter is able to circulate optimally.
In addition to cost, the size of the Fluval Canister Filter can also present a challenge. If you decide to use a Fluval Canister Filter, it is important to make sure you have plenty of space behind or below your tank for this monstrosity.
3. EHEIM Classic Canister Filter
The EHEIM Classic Canister Filter is new on the market, and therefore not as well-known as some of the others on this list. However, it is a durable filter with strong filtration power and an impressive flow rate of 165 gph, allowing it to easily keep up with the bioload of a larger turtle.
EHEIM Classic Canister Filters come with everything you need to start, including the filtration mediums. However, unlike many other filtration systems on this list, the EHEIM Classic Canister Filters only come with biological and mechanical filtration, not chemical filtration.
The EHEIM Classic Canister Filter is unmatched in its sturdiness. With thick plastic components and stainless steel clasps, this filter is likely to outlast any other component of your tank system.
The largest drawback of this filter is its polishing pad. Though the mechanical component of this filter makes your tank appear immaculate, it is also prone to clogging because it was not designed with the turtle’s large organic matter in mind. However, with routine maintenance, you should have no real issues with this filter.
Additionally, while the EHEIM Classic Canister Filter stands up in quality to other canister filters on the market, it does not offer as many varieties as the Penn Plax or Fluval Canisters, so it is only available for a small subsection of tank sizes.
Best Hang-on-Tank Filters for Turtle Tanks
1. Tetra Whisper EX Power Hang-on-Tank Filter
The Tetra Whisper EX Power Hang-on-Tank Filter is advertised for 40-75 gallon tanks, making it perfect for small turtle tanks up to 35 gallons. It has a longer input pipe than most hang-on-tank filters, allowing tank water to sit 3 to 4 inches below the top of the tank. This helps guarantee that your turtle will not be able to pull itself out of the water over the side of your tank.
The Tetra Whisper works well with floating or external basking areas. However, if you use the Tetra Whisper in your tank, you must ensure that your turtle cannot use its basking area to escape the tank.
As the name suggests, the Tetra Whisper is a relatively quiet filter that is perfect for turtle tanks located in bedrooms or family rooms. It is also relatively easy to set up and maintain, making it perfect for beginning aquarists.
The Tetra Whisper also comes with multiple filtration media, providing mechanical, biological, and chemical filtration. Thanks to the popularity of Tetra filters with fish aquarists, it is also relatively easy to find new filtration media in local pet stores and online.
The largest downside to the Tetra Whisper is that it doesn’t have the filtration power needed for larger turtle tanks. As a result, you will likely need to use multiple filters or switch to a larger filter as your turtle grows.
2. Penn Plax Cascade Hang-on-Tank Filter
The Penn Plax Cascade Hang-on-Filter is available for 50-100 gallon tanks, making it a great filtration option for turtle tanks up to 50-gallons in size. The Penn Plax Cascade is one of the strongest hang-on-tank filters in the market, with a flow rate of 300 gph.
Penn Plax Cascade filters have a multi-stage filtration setup that provides mechanical, biological, and chemical filtration. The filtration media is easy to access and replace, making setup and maintenance fairly easy for beginner aquarists.
The largest downside to the Penn Plax Cascade Hang-on-Tank filter is its short input piping. The short piping means that the water level must be nearly parallel with the top of your tank. Therefore, the Penn Plax Cascade Hang-on-Tank Filter should only be used with an external basking area to ensure the safety of your turtle.
Best Submersible Filters for Turtle Tanks
1. Aqueon Quiet Flow Submersible Filter
The Aqueon Quiet Flow Submersible Filter is a sleek, black filter that attaches to the inner walls of your aquarium. The filter can be placed on the wall vertically or horizontally. The output flow piping can be rotated to allow it to be above or below the water. The flow rate of the filter can also be adjusted.
The Aqueon Quiet Flow comes with a four-stage filtration system. In addition to the biological, mechanical, and chemical filtration media, the filter also has a wet/dry diffuser grid that prevents clogging. This is very beneficial for turtle tanks, as the organic matter is typically larger than what filters are designed to accommodate.
This filter is great for beginners, as all the media comes pre-packed. However, this means that you will not be able to customize your filtration media.
As the name suggests, the Aqueon Quiet Flow was created specifically to be a silent filtration system. This makes it incredibly useful if your tank is in your bedroom or main room.
The biggest downfall of the Aqueon Quiet Flow is its size. The Aqueon Quiet Flow is made for tanks ranging from 10 to 40 gallons, which means it is only strong enough for a 10-20 gallon turtle tank. However, thanks to its incredibly small size, you can easily use several of these small filters throughout your tank.
Using multiple filters will help you maintain consistent water quality throughout your tank, and also allows you to clean your filters without completely stopping the filtration within your tank.
2. Fluval Submersible Filter
The Fluval Submersible Filter is one of the strongest submersible filters you can buy. It comes in a range of sizes and is advertised for tanks up to 65 gallons. As a result, a single Fluval Submersible Filter is typically strong enough for turtle tanks up to 40 gallons. However, like the Aqueon Quiet Flow, the Fluval Submersible Filter is small and sleek enough that you can easily use multiple filters within your tank.
The Fluval Submersible Filter comes with an adjustable flow-control valve that allows you to control the force and direction of your output flow. It also comes with pre-packaged filtration media that includes mechanical, biological, and chemical filtration. It is easy to set up and maintain, making it very accessible for beginner aquarists.
One of the largest complaints about the Fluval Submersible Filter is that, because it doesn’t have a wet/dry diffuser grid, it is more likely to clog when accosted with the larger bi-products of turtles. However, with periodic maintenance, this issue can be easily mitigated.
3. Tetra Turtle Decorative Filters
The Tetra Turtle Decorative Filter is listed as a submersible filter. However, in actuality, it doesn’t really conform to any of the typical filter types. The Tetra Turtle Decorative Filter is a filter specifically designed with the needs of semi-aquatic turtles in mind.
The Tetra Turtle Decorative Filter is a filter built into a rock feature. From the outside, this filter looks like a beautiful rock and waterfall feature for your tank. However, as it pushes water up for the waterfall, it also performs the necessary filtration.
The Tetra Turtle Decorative Filter comes with a three-stage filtration process and is designed to work in water as shallow as six inches. The filter itself is relatively quiet, and is almost imperceptible over the sounds of the waterfall.
Like all the submersible filters on this list, one of the biggest downfalls of the Tetra Turtle Decorative Filter is its size. The filter has a flow rate of 50 gph, making it useful only for small turtle tanks.
If you are planning on using multiple submersible filters in a larger tank, the Tetra Turtle Decorative Filter is a great addition to one of the other submersible filters on this list.
FAQs About Filter for Turtle Tanks
Do Turtle Tanks Need a Filter?
Compared to most aquatic creatures, turtles have a relatively high bioload. Without a filter, the leftover food and excrement from your turtle will muddy your tank and detrimentally impact the water chemistry within a day or two. Therefore, for both the aesthetics of the tank and the health of your turtle, a strong filtration system is a necessity for your turtle tank.
What is the Best Kind of Filter for Turtle Tanks?
The best filters for turtle tanks are canister filters. Canister filters are external filtration units that are capable of pumping and filtering much more water than other filters. Turtles are relatively large creatures with high bioloads and larger tanks. As a result, they need a filtration system that can keep up with their needs.
What Types of Filtration Are Required for Turtle Tanks?
Turtle tanks require biological and mechanical filtration. While chemical filtration is not required, it is recommended for the health of your turtle.
Can You Use a Fish Tank Filter for a Turtle?
Surprisingly, there are very few filters made specifically for turtle tanks. As a result, you will likely end up using a fish tank filter for your turtle tank.
If you are using a fish tank filter, it is important to remember that the recommended tank capacity for the filter is based on the bioload of fish. Therefore, you will want a filter that is recommended for a tank 2-3 times the size of the turtle tank you are using.
Can I Turn Off My Turtle Filter at Night?
You can turn off your filter at night. However, be aware that the longer you keep your filter off, the more quickly your tank will need maintenance. Therefore, it is best for both you and your turtle to keep the filter running as much as possible.
How Often Should I Clean the Filter in My Turtle Tank?
The amount of maintenance that your filter will require is based on a number of factors, including the size of your filter, the size of your tank, and the bioload of your tank inhabitants. In general, most filters need to be cleaned every 2-4 weeks.