Are Canister Filters Good for Reef Tanks?

In the fresh water sector, canister filters have long been the go-to filtration choice for bigger tanks. Are they, however, suitable for saltwater aquariums? Let’s have a look.

But first, let’s have a look at how they function. At their most basic level, canister filters are fairly simple. They have many baskets for various types of filter media. In addition, there’s a little circulation pump hidden inside a small casing.

The pump takes water from the tank through the inlet tube once the initial siphon is established. After that, it goes through a series of mechanical, chemical, and biological filtration steps.

When it reaches the canister’s end. The water is pumped out and returned to the tank through the output tube. One of the most significant drawbacks of canister filters is how difficult they are to clean. A canister filter, like other aquarium equipment, collects waste and debris over time. This implies that it will need to be cleaned on a regular basis. Unfortunately, water fills the canisters, and there isn’t a good method to drain it.

Depending on the model you’ve got. To keep the drain siphon going, most filters offer a way to seal the intake and outlet. While still allowing the filter to be moved away from the tank First and foremost, you must unplug the filter in order to turn off the filtration pump. The inlet and outlet tubes should then be unlocked and removed. Remove the now-disconnected canister and place it in a sink, outside, or wherever you choose to complete your aquarium care.

You can drain the filter and remove the media from here.


Check your mechanical and chemical filters and, if necessary, replace it. Examine your biological media to see if it has begun to collect garbage. Take either the water you’ve drained from the filter or the water you’ve emptied from the filter if it’s gotten too unclean. Alternatively, rinse the media in freshly mixed salt water. If you don’t clean the biological media with salt water, you’ll kill the bacteria that have colonized it. While the filter is still open and empty. Rinse the body thoroughly and make sure it is free of particles.

Replace the media and reconnect the canister to your tank after everything is clean. It’s also a good idea to have freshly mixed water on hand. Because you’ll need to replace whatever you’ve previously drained from the filter.

So, why do canister filters receive a poor rap in salt water tanks? In a fish-only aquarium, you can surely utilize a canister filter in conjunction with a protein skimmer. Regrettably, this isn’t always the case when it comes to reef tanks.

When coral is added to a tank, things become a little more complicated./a> Unfortunately, canister filters fall short of the performance of sumps in these situations. To begin with, sumps contain a lot more water than canisters, significantly increasing the total volume of your system. And you’ll have a lot more control over your parameters. Second, when compared to a sump, the canister simply does not have enough surface area for bacteria to grow due to its small size.

Fill your canister largely with biological media to combat this. Even so, there may not be enough room to compensate for the disparity.

Because fish are less finicky than corals. For fish solely in live rock tanks, a canister filter is likely to be a better choice. Keep in mind that you’ll still need to maintain it on a regular basis and replace your media on a regular basis. Otherwise, you run the risk of it becoming a nitrate factory. Despite these drawbacks, canister filters can be used in marine aquariums. However, they’re better saved for nano-tanks, where a sump isn’t feasible. Canister filters have a variety of functions in the hobby aside from being a permanent filter for your tank.

We have a wide selection of canisters from Eheim, Fluval, and Zoo Med that are suitable for both saltwater and freshwater use. They all lead to the same destination, but each has its own set of attributes that may or may not appeal to you. In the comments section below, tell us how you’ve set up a canister filter and what kind of media you use with it.