The Best Filter for Turtles in the World main picture
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If you have an aquatic turtle, you’ll need a good filter. I have tried quite a few, and I would pick this as the best filter for turtles.

I’ll get straight to the point.

If you have an aquatic species of turtle, such as a red-eared slider or a painted turtle, I would highly recommend getting a canister filter. They are perfect for larger aquariums and sit under or next to them, maximizing space. The best canister filter for turtles that I have used are Fluval filters, followed by any of the Penn Plax series filters.

Based on my experience, this is how I would rank the best turtle filters.

The Best Filter For Turtles

Turtles are messy creatures. In fact, they are much messier than other types of pets.

Because of this, many pet turtle owners think that dirty, muddy water is still OK for turtles. And while turtles are able to live in dirty water much easier than other types of animals, this isn’t healthy.

Now, before you go out to purchase just any tank filter, you need to be aware of a few key things.

Follow this rule! You need the biggest tank you can get. Unlike fish, turtles do in fact outgrow their enclosures. Just because you bought a 30-gallon tank doesn’t mean your turtle will stay at 4 inches. And the bigger your tank, the more powerful the turtle filter you need.

What Kind Of Filter Do I Need For A Turtle Tank?

There are lots of different types of filters:

  • Canister filters
  • Undergravel filters
  • Power filters

Although they are large, bulky and a bit expensive, canister filters are far and away the best investment you can make for indoor aquariums that house aquatic turtles.

Here’s why:

  1. Indoor aquatic turtles need the largest possible aquarium you can afford, and canister filters are really the only type of filter that can handle this much water.
  2. Canister filters typically sit underneath or next to your aquarium, which maximizes space.
  3. Canister filters have multi-level filtration systems that are necessary to clean up the huge amount of waste that your turtle produces.

That being said, here are a few rules to follow for canister filters.

You Need A Powerful Canister Filter

Here’s a good rule of thumb when it comes to narrowing down your list of filters.

Whatever the water capacity of your tank, try to double or triple it when it comes to your filter.

What does that mean?

If you’ve got a 55-gallon tank, you should try to get a filter that is rated for at least 110 gallons.

You need the full capacity, times two or three. At the very least, your filter should be rated HIGHER than how many gallons are in your tank.

There are a few reasons for this but essentially, turtles are incredibly messy creatures and when you start adding things, like more fish or plants, it will add to the filter load quickly.

You Need A Biological Filtration System

This is the most important part of your filter process.

Turtles excrete a ton of ammonia through their waste.

If not treated and filtered, that ammonia then builds up rather quickly in the tank and is very harmful and toxic to your turtle.

In a biological filtration system, that ammonia and waste is sucked in through the filter and run through a sponge or other type of media that contains a good bacterial colony (that builds up slowly) that breaks that ammonia down into nitrite.

Unfortunately, that nitrite is also quite toxic and harmful to your turtle.

However, there is also a different type of bacterial colony that also grows on the filtration media that then breaks that nitrite down into nitrate, which is much less toxic and harmful to turtles.

In a biological filtration system, that ammonia and waste is sucked in through the filter and run through a sponge or other type of media that contains a good bacterial colony (that builds up slowly) that breaks that ammonia down into nitrite.

This is also why it is so important for you to regularly change and clean your turtle’s tank, even when you have a biological filtration system.

Nitrate is much less harmful to your turtle, but it can still be harmful if it builds up to too high of a level.

You Need A Good Mechanical Filtration System

Mechanical filtration is what most people think of when they think of filters.

This type of filter cleans up all the particulate matter in the tank, things such as;

  • Animal waste.
  • Crud and gunk.
  • Excess and decayed food.

This type of filter cleans up all the particulate matter in the tank, things such as; animal waste, crud, gunk, excess, and decayed food and anything else floating in around there.

Basically, it makes your turtle tank water look clean. It’s also a lot easier when you don’t have any substrate (rocks or gravel) at the bottom that can be sucked up and clog the filter.

About Chemical Filtration

This is sometimes seen as a luxury and not a necessity, next to biological and mechanical filtration.

What chemical filtration does is use a chemical media to break down any excess material that gets sucked up through it.

Two common examples are activated carbon (which helps break down organic matter) and ammonia removers (which helps break down ammonia), although both of them can and sometimes do interfere with the biological cycle.

What chemical filters really excel at is making your tank water look very clear and crisp.

What Kind Of FiltersTurtles Don’t Need

When it comes to purchasing a good filtration system for your tank, you’ve got quite a bit of good options.

That said, you’ve also got a lot of bad ones. Here are a few things to stay away from.

Undergravel filters.

They might be OK for fish, but for turtles, they are a no-no. Most of them do have biological and mechanical filtration, and work by sucking down particulate matter through your substrate on the bottom, cleaning and releasing it back to the top, but the good ends there.

For one, turtles love to dig, and that digging will not only eventually clog your filter but kick up all the bacterial growth that rests on the filter.

Filters made for fish and small tanks.

Steer clear! Quite honestly these should not be used by fish, but people unfortunately, buy them because they are cheap. They clean up large particulate matter, but that’s about all they do.

What Type Of Filter Is Best For A Turtle Tank?

Like I said, if you are looking to get a good filter, look at canister filters. A turtle canister filter is typically much, much more powerful than other types of filters, such as power filters and under gravel filters.

A word of caution:

Warning. You would be wise to only purchase a filter that comes with a warranty!

Your filter is probably going to be the most expensive thing that you buy for your turtles.

Thus, you don’t want to fork over your hard-earned money for a product that is just going to break after a few months or worse yet, arrive with a broken part.

Filters, just like any other machines that are built with a lot of moving parts, sometimes break. While I don’t want to scare you and tell you that it is a common thing, it does happen.

This is why it is crucial for you to only choose a filter that comes with a warranty. And the stronger the warranty, the more relaxed you can feel.

I have found that you have to be careful here, even with the warranty. Sometimes companies will provide warranties, but they only apply to things like the motor.

Or, the customer service line is manned by workers who are not fluent in English and aren’t very well-versed with the product

Thus, it is absolutely crucial that whatever filter you choose, it comes with a good, reliable and preferably multi-year warranty.

The Fluval Series of Filters

The Fluval series of filters are my personal favorite, for a few reasons; they come in a ton of sizes (from 25 to over 100 gallons, they come with filter media (and has lots of options) and best of all, they have a 3-year warranty (a MUST).

In my opinion, they are excellent turtle filtration systems for novices and beginners alike.

  • It comes with filter media and has a ton of options for further filter media.
  • Multi-stage filtration process.
  • The self-priming feature automatically vacuums out any excess air every 24 hours.
  • Very powerful filters, the 106 model starts filtering at 145 GPH (gallons per hour) all the way to the 406 model, at 383 GPH.
  • It offers a selection of higher-powered filters for much larger tanks, from 100 gallons all the way up to the 400-gallon FX6 Filter.

These turtle aquarium filters are a little more expensive than the others, however, I can attest that the quality is the best, and they have the strongest warranty of all the other filters out there, at 3 years.

If you are looking for the best filter for a 100-gallon tank (or bigger), then I would strongly suggest looking at Fluval’s series first. The bigger your tank, the more you’re going to need to invest in a high-quality filter (unfortunately).

TableUsed for this many gallons
Fluval 10625 gallons (suitable for a 10-15 gallon turtle tank)
Fluval 20645 gallons (suitable for a 20-25 gallon turtle tank)
Fluval 30675 gallons (suitable for a 30-40 gallon turtle tank)
Fluval 406 100 gallons (suitable for a 50+ gallon turtle tank)

Here’s how they work. Water flows through 3 sets of foam filters, which filter out most particular matter. The inside pump then pushes water through whatever media stacks you have chosen for your aquarium (any combination of biological, chemical and additional mechanical filtration).

If you are looking for something that is just as high quality but not as expensive and for a little smaller of a tank, check out their 406 model, which is great for up to 100 gallons.

The Fluval series of filters are my personal go-to and if someone asks me what is the overall best, Fluval would be that.

However, Fluval filters are considered to be quite expensive, and so if you are looking for a less expensive, but still reliable alternative I would strongly suggest any of the Penn-Plax Cascade series.

The Penn-Plax Cascade Filters

In my opinion, the Penn-Plax Cascade series of turtle water filters are excellent alternatives to the Fluval series:

  • Large capacity stackable trays to allow for multi-stage filtration.
  • Quick and easy push-button primers.
  • Adjustable water flow valves.
  • Tons of options for additional media filtration.

The Penn-Plax Cascade series of filters are excellent alternatives to the Fluval series. There are filters for nearly every tank size (from 30 gallons all the way to 200 gallons), come with starter filtration media, have a 3-year warranty with an American English customer support line and are slightly cheaper than the Fluval series, ranging from $60 to $160.

These filters come in the following sizes:

NameUsed for this many gallons
Cascade 50030 gallons (suitable for a 15-20 gallon turtle tank)
Cascade 70065 gallons (suitable for a 30-40 gallon turtle tank)
Cascade 1000100 gallons (suitable for a 50-60 gallon turtle tank)
Cascade 1200150 gallons (suitable for a 75 to 90 gallon turtle tank)
Cascade 1500200 gallons (suitable for 100+ gallon turtle tank)

EHEIM Filters

If you don’t recognize the EHEIM brand, you probably haven’t been around the pet world for a while. EHEIM is known as having top-notch quality.

However, I would recommend that you look first at the Fluval and Penn-Plax brands first, simply because you will have a lot more options.

The EHEIM series of filters come with a 2-year warranty and starter filtration media, but don’t have as many choices in terms of gallon sizes.

The EHEIM Classic series of turtle aquarium filters are great starter canister filters that will be reliable and easy to work with:

  • Can filter from 42 to 92 gallons.
  • Cheaper than the Fluval filters but still extremely effective.
  • It comes with starter filtration media.
  • This filter also comes in different models for different sized tanks and needs (like the Fluval).

These filters run from $70 to  $120.

NameHow many gallons
Classic 4040 gallons (suitable for anything lower than 25 gallon turtle tank)
Classic 6660 gallons (suitable for a 30-35 gallon turtle tank)
Classic 9292 gallons (suitable for a 40-50 gallon turtle tank)

Sun Sun Filters

Next down the list are these Sun Sun series filters. Compared to the Fluval series, they are quite a bit cheaper, and they are also cheaper than the Penn-Plax series as well. The Sun Sun filters start at $40.

The Sun Sun series turtle filters have been greatly recommended among pet turtle enthusiasts for a while now.

They are excellent, less expensive alternatives to the Fluval series.

If you are looking for something that is just as high quality but not as expensive and for a little smaller of a tank, check out their 406 model, which is great for up to 100 gallons.

Stay clear of the 104-5 and 204-5 models as they are not powerful nor have as many stacks as the Fx6 or 405-6 (although they will do fine for fish).

  • It is perfect for a 50-gallon turtle tank, all the way up to a 150-gallon tank.
  • Cheaper than the Fluval filters but still extremely effective.
  • It comes with filter media; sponges, rings and bio-balls.
  • This filter also comes in different models for different sized tanks and needs (like the Fluval).

These filters run from $40 to over $100.

If the turtle filter comes broken, Sun Sun will replace it for free, however, as Sun Sun is a Chinese company, you will have to deal with their sometimes spotty customer support line.

NameUsed for this many gallons
HW-302 Pro75 gallons (suitable for anything less than 40 gallon turtle tank)
HW-303B100 gallons (suitable for a 50-60 gallon turtle tank)
HW-304B150 gallons (suitable for a 75-100 gallon turtle tank)
HW-702B75 gallons (suitable for anything less than 40 gallon turtle tank)
HW-704B150 gallons (suitable for a 75 to 100 gallon turtle tank)

The Best Internal Filter for a Turtle Tank

An internal filter is, like its name suggests, basically a filter that does not connect to any tubes running into a canister that sits outside of the tank. With most models, you simply submerge it underwater and attach it to the side of your aquarium, plug it in and you’re good to go.

Personally, I would not recommend using an internal filter in most cases unless:

You have a smaller aquatic turtle, such as:

  • A (common) musk turtle.
  • A mud turtle (such as the Mississippi).

Many species of musk and mud turtle do not grow larger than 4 to 5 inches and can be safely put into an aquarium that is no more than 30 to 40 gallons.

Assuming your aquarium is 40 gallons or smaller, here is what I would recommend as the best internal filter for turtle tanks:

Fluval Underwater Filter 

These would be my first recommendation for an underwater filter, as:

  • It is available for different types of low-gallon tanks (Up to 15 gallons, 12-30 gallons, 24 to 40-gallons, and 34 to 65 gallons).
  • Are extremely quiet.
  • Have a 3-stage filtration system process that includes biological media.
  • Have adjustable flow-control that is also powerful enough to clean up a 30-gallon tank housing a messy turtle.

As I noted above, Fluval filters also come standard with 3-year warranties, which as of 2019, is quite exceptional compared to their competitors.

While it’s a pretty powerful, reliable filter for the smaller tank sizes, I would suggest that if your tank is close to or above 40-gallons and you have other fish or plants, moving up to a canister filter or something a little beefier.


These take a little bit of getting used to, but once you get the hang of it, it will easily last for years as a strong filter for your system.

There are other options as well, but if you are looking for something that has a proven track record of working well, we would strongly urge you to check out one of the three models above, based on the size of your tank.

You might be tempted to go with a generic brand for your turtle aquarium filter, but I would actually advise against that, for a number of reasons.

Generally, customer support is not nearly as good with generic brands vs. brands such as Fluval or SunSun. That is if you can even reach them. Secondly, most generic, cheaper brands lack any type of warranty or use an extremely limited one.

Next, there is the issue of user experience. A good Fluval or SunSun filter is going to be expensive yes but there are also thousands of people who have bought these products, and thousands of people who have used them reviewed them, and understand them well. With a more generic filter, this doesn’t exist. Everything is up in the air, so getting help or getting someone to answer even a basic question of yours is often problematic.

If you are looking for the best filter for turtles, it’s best to make a little investment and just go for a Fluval or Penn-Plax, you really can’t go wrong with either.

About the Author

Hi, I'm J and I'm the chelonian-obsessed creator of this website. Feel free to leave a comment below, as unlike a snapping turtle, I promise I won't bite!

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