Finding Canister Filter For A 20 Gallon Tank
If you’re looking for help with picking a canister filter for a 20 gallon tank then keep reading….
The following is a question from one our TFCG community members.
Question: “Hello, I’m looking for a canister filter for a small aquarium, but I’m worried that a canister filter will be too strong.
What size canister filter do I need for a 20 gallon tank?”
In this post you will learn how to select a canister filter that will be perfect for your 20 gallon tank and not break the bank doing it.
Here are the top four average priced canister filters for a 20 gallon tank:
- Penn Plax Cascade 500 Canister Aquarium Filter
- Fluval 106 External Canister Filter
- Marineland Magniflow 160 Canister Filter
- Eheim Classic Canister Filter with Media – 2213
If you’re thinking of using a canister filter in your 20 gallon tank you may have thought…
Is a canister filter too strong for a 20 gallon tank?
If that’s you, don’t be concerned.
A canister filter can help keep your 20 gallon tank clear and clean and in my opinion is the better option over any other filter set up.
In general, the main difference between canister filters and power filters is the amount of water that can be processed per hour.
As an example;
The Marineland Penguin Power Filter can filter 150 GPH, whereas the Marineland Magniflow 160 Canister Filter will run 160 GPH.
Both are good but as you can see the Marineland Magniflow can process more than the Marineland Penguin Power Filter.
But flow rate is not really what makes a filter efficient!
What really sets apart canister filters from power (HOB) filters is the media area available for beneficial bacteria to grow on.
“Canister filters have a far superior advantage when it comes to media capacity when compared to other filters.”
Canister filters have huge trays which allow you the ability to provide all the filter media options you can think of.
How to Pick a Fish Tank Filter
Okay, okay, but can you over filter a fish tank?
In my experience, no.
The more filtration the better.
I personally have a 20 gallon aquarium with a canister filter rated for a 75 gallon tank and it keeps the tank crystal clear.
So how do you determine the right size canister filter for your tank?
In general, the rule of thumb is that your filter should pass all the water in your tank through the filter at least four times per hour.
As an example;
If you have a 20 gallon tank, you should have a canister filter with a flow rate of at least 80 gallons per hour.
If the filter choices are between 80-100 gallons per hour, you should always move to the higher flow rate.
Most aquarium canister filters will show you on the box the intended tank size along with the flow rate usually in gallons per hour.
Here are four canister filters that follow our rule of four and have a flow rate of at least 80 gallons per hour which would be well suited for a 20 gallon tank: