Best Canister filter for Red-eared slider 2018

Best Canister filter for Red-eared slider 2018

Canister filters are perhaps the most popular type of filters used by red-eared slider enthusiasts. These are excellent for tanks 40 gallons or more. Canister filters cover all aspects of a good filtration system. They offer exceptional mechanical, chemical and biological filtration. The housing tank is known as the canister, are also larger than most hanging filters on the market.

Selecting the most appropriate canister filter for your turtle is very important. This will impact the quantity of the water as well as the wellbeing of your red-eared slider. Not only that, The amount of maintenance required also differs.


What is a Canister Filter?

Fluval 206

Canister Filters provides superior filtration that is suited for large or heavily-stocked aquariums. Canister filters are units that make use of both pressure and gravity, making them one the best red-eared slider filter. As compared to hanging filters that rely solely on the law of gravity for the flow of water through its filtration media, Canister filters are sealed and pressurized. This means water is forced through the filter pads, creating a more effective overall filtration.

The main unit is located outside the aquarium, it maximizes filtering capacity by taking advantage of their large filter body allowing more swimming space in your red-eared slider tank. The best canister filter for your turtle performs all three forms of filtration. Being Mechanical, Chemical & Biological filtration.


Filtration process of the canister filter

The filtration process of the canister filter for your turtle tank begins with the mechanical filtration.

Mechanical filtration is the process where particles like solid wastes or leftover food are cleared from your red-eared slider tank when water is cycled. Red-eared slider turtles are known to be very messy eaters. If the wastes are left uncleared, it will eventually decompose any produce loads of ammonia that adversely affects your turtle’s health.


Mechanical filter pads & floss

Aquarium Filter RollFilter floss



Ammonia Neutralizing Crystals Next would be Chemical filtration. The water is forced through the foams or filter pads onto the chemical filtration chamber which houses a combination of activated carbon and Ammonia Neutralizing crystals. Chemical filtration removes discoloration, odors, and other chemicals from your red-eared slider turtle tank. The process is known as adsorption. Adsorption is the process where the carbon will ledge on and stick onto certain chemicals in your turtle tank. The chemicals are “grabbed” and prevented from re-entering your turtle tank.


The final phase of the filtration process would be biological filtration. Biological filtration is the process of breaking down various bacteria in your red-eared slider tank.  This is known as the nitrogen cycle. The nitrogen cycle is the process where ammonia produced by your turtle and leftover food bits are converted into Nitrite and to Nitrite.

Ammonia is extremely dangerous your turtle even in low concentrations. Hence, the biological filtration process is vital to the health of your turtle. A thriving bacteria colony that can effectively cycle through the ammonia.

Upon completion of the filtration process, the water will be siphoned back into the turtle bank via a water tube.

read also : What is the Best filter for my Red-eared slider tank??

Pros & Cons of canister filters for your turtle.

Advantages of using a canister filter

There are many advantages of using a canister filter for your red-eared slider.

Increased water volume

First off, Due to the large chamber of the canister filter, the total water volume in your whole aquarium ecosystem is increased. The Higher volume of water reduces the concentration of ammonia and other toxins. The PH will also be more stable as a result of higher water volume.

canister filters can significantly increase the total volume of water in the turtle tank setup due to its large chambers. The increased water volume in your red-eared slider tank means that the concentration of impurities and ammonia are lower. It also means a more stable water quality such as pH level, hardness as well as temperature.

The external canister also provides a higher volume of filter media without reducing the internal space in your turtle tank. It can be disconnected from the tank for cleaning and maintenance with minimal disturbance to your turtle

Spacious chamber to house media

Compared to other forms of the filtration system, the canister filter has the largest chambers to house your various media. This allows housing a different combination of media for each filtration stage. For example, using a combination of filter pads & floss for mechanical filtration. The filter pads will trap larger debris before the water flow to the floss to sift through the finest particles more effectively.

The spacious chamber also lets you pack more chemical media such as carbon & ammonia neutralizing crystals and biological media. A large chamber increases the amount of Bio-media to build a larger nitrifying bacteria community.


Swimming space for your turtle

having the whole canister outside of your turtle tank reduces clutter in the turtle’s living habitat. Not only does it creates more swimming space for your red-eared slider turtle, it is also much more aesthetically pleasing not to have a chunk of plastic within your turtle tank.

Check out this incredibly huge turtle tank with so much swimming space!


Canister Filter Drawbacks

The main cons of a canister filter would be maintenance. In a full-fledged canister filter for your turtle, there are various compartments and chambers compromising of baskets, cartridges, media bags and various paddings. All these will need to be taken apart for cleaning during maintenance.

Although the canister filter may require more work to set up and maintain, the effectiveness and flexibility it offers are worthwhile. The worst thing you can do is to leave a clogged and dirty canister filter unattended. Not only will it affect the water quality of your turtle tank setup, it will also significantly shortened the lifespan of your canister filter.

Once you are familiar with the inner workings and mechanisms of your canister filter, the maintenance routine would be a lot easier and less time-consuming.


Misconceptions about Canister filters

One common misconception about canister filter is that the biological filtration is mediocre and less effective compared to other systems such as the wet-dry filter setup. This misconception arises due to the water level within the biological media chamber. As the media are being submerged in the water, there is a lack of air to water interaction. Adequate air to water interaction allows the bacteria colony to thrive effectively. However, this would usually only apply more to bio-balls. Ceramic rings’ extremely porous nature creates a massive surface area to colonize bacteria effectively on and inside each ring. This design also allows maximum water flow. The rings are fully submerged to let the whole surface area to be in contact with the water. This allows effective colonization of beneficial bacteria.

What to consider when buying canister filter for your turtle.


Depending on the brand capacity of the canister filter for your turtle, the cost can vary a lot. A canister filter of the same flowrate already costs considerably more than its other counterparts such as an internal filter. But bear in mind that canister filters are way more efficient and superior than internal filters of the same specifications.



We are not trying to be brand conscious here. But there is a reason why certain brands are much more well-known and popular in the market. Well, advertising and heavy marketing may play a part. But ultimately, the main reason these brands thrive compared to others has to be quality. Only by ensuring top quality in the products they offer, can the brand be able to sustain its reputation. Having a good quality filter will also ensure that the filtration system for your turtle tank works all the time. Remember, red-eared sliders create a lot of mess and waste. You can’t really afford to have a low-quality filter that breaks down all the time.

By no means are we saying that companies that are less reputable produce lower quality goods.

However, if it is too much trouble for you to conduct such in-depth researches and comparison, it is much safer to go with a reputable brand.


How big is your tank

The size of your turtle tank determines how much water is required. This will impact the flow rate of the canister filter for your red-eared slider. The flow rate is measured in gallons per hour (GPH). This measurement represents the maximum number of gallons of water can pass through the filter per hour. Filter flow rate will determine how efficient water movement throughout the aquarium.

The flow-rate of a filter can usually be identified by the label on the filter box. The label would usually come with a recommendation on what tank size the filter is most suited for.


How many turtles do you have

Although usually the labels on the box would give a rough guideline on a capacity of the filtration system, Bear in mind that the recommendations are usually meant for an aquarium that houses fishes. Red-eared sliders are much messier compared to goldfishes. So, you should always get a filter with water flow rate that is meant for a bigger tank, or the best filtration you can afford without burning a hole in your pockets.



Another very important aspect to consider when buying a canister filter for your turtle would be the warranty. Before you make any purchase, be sure to check with the retailer if the product carries any warranty period, and how long is the validity. This is especially true if you happen to stumble upon a deal on products that are priced significantly lower than the market price. Often times, businesses may be able to reduce cost by importing certain products from other countries with a more competitive price. The tradeoff however, would be the lack of warranty.

Although the chances of a quality filtration system breaking down within the first few years are low, it is really not worth the risk to forego the warranty and end up spending much more to buy a brand new set should the current one dies.

Do you have other filters?

It is always good to have a secondary filter in your aquarium. A secondary filter (usually internal filters or under-gravel filters) can help share the load of your existing canister filter. This can increase the overall effectiveness of your filtration and reduce the frequency of maintenance. With a good secondary filter, you may be able to slide by with a less powerful canister filter. Although there is never too much when it comes to GPH of your filter.

Do you have enough space?

One of the main features of canister filters is that the housing unit is outside of the tank. While some canisters are not as big, more powerful canister may take up a considerable amount of space. Be sure to check on the size of the filter that you are about to buy. This information would usually be available on the label. Else, you can always do some research on the internet and do some measurements of your own. Also, you may have to purchase a cabinet or stand in order to house your canister filter properly.

Aquarium Stand


 So What’s the best canister filter for my turtles?

We have broken down our individual picks for the most suitable canister filter for your red-eared slider tank based on your tank size.

Up to 55 G tanks 

Marineland Magniflow Canister

Marineland Magniflow Canister


The Magniflow Canister Filter 220 is a powerful, multistage filtration system that is ideal for your red-eared slider habitat. This multistage filtration gives your water a clear and healthy living environment for turtles. It may be the smallest and most compact canister filter on this list, but don’t let its size fool you. The Marineland Magniflow Cannister filter packs a real punch!

The polishing filter pads at the mechanical filtration stage effectively remove fine debris such as food wastes and excretions from the tank. The second biological filtration stage features bio-filter balls as well as ceramic rings for strong growth of the bacterial colony. The final layer will be used to house chemical media such as carbon to remove odors, discolorations, and impurities.


Up to 90G tanks 

Eheim Classic External Canister Filter 2215

Eheim Classic External Canister Filter 2215

The Eheim Classic canister filter is carefully tailored external filters for aquariums of up to 90 Gallon and are equipped with superior quality parts. The Classic canister filter provides a low cost and reliable filtration system for your red-eared slider turtle tank.

Over the years, the Classics have built up a known reputation for EHEIM as a highly reliable canister filter with an excellent price tag.



Up to 150G tanks 

Flexzion HW-302 Canister Filter

Flexzion HW-302 Canister Filter

The Flexzion Sun Sun canister filter works best for tanks of around 150 gallons. It features a very high water pressure and very strong powered pump that pumps an amazing 525 Gallons of water per hour, making it the most powerful and highest workload canister filter in our list.

The water in your turtle tank is fed into the canister for a double filtration 3 media trays that are more than capable of handling all types of filtration methods. It also Comes with an adjustable spray bar that lets you adjust the output flow to your liking.

The Fkexzion Sunsun canister filter provides superior filtration ideal for heavily-stocked tanks. We also love the fact that there is a UV sterilizer function. The UV sterilizer helps sterilize the water in your turtle tank.

BIG TANK 250 G tank



The API FILSTAR xP is an extremely powerful, yet super easy to operate filtration system. Despite its enormous workload, it is very quiet and can be placed in any area of your house.

What we like best about this the API FILSTAR xP is its capability of self-priming. This system primes itself up within seconds with no hand pumping or manual siphoning required. The whole process is so easy that no technical knowledge is required. There is also a Patented anti-airlock system that eliminates the need to re-prime.

The Self-locking water shutoff system also prevents any accidental flow of water during maintenance of your turtle tank.

The superior and quality design of the API FILSTAR XP cannister filter makes it one of the most reliable canister filters in the market. Its strong built ensures a hassle-free and quiet operation with minimal disruption. Its strong flow rates and superior filtration media provide optimal filtration results with super easy maintenance.


Up to 400G tank!

Fluval FX-4 or FX-6 Aquarium Canister Filter Package

Fluval FX-4 or FX-6 Aquarium Canister Filter Package


The Fluval FX6 is the highest performance canister filter on our list with outstanding features specially designed to make the upkeep of your red-eared sliders super easy and convenient than ever. This extremely huge capacity yet minimalistic designed canister filter has a pump output of an impressive 925 gallons circulation of 563 Gallons per hour.

A total of 5.9 liters of water can be held within the baskets of the canister. Together with the Smart Pump Technology by Fluval which uses an electronic circuit board to continually observe and monitor the pumps to ensure consistent and powerful output. With a really large turtle tank, powerful performance such as the Fluval FX would be a wonderful choice for your red-eared slider turtle tank!