Do Goldfish Need A Filter?

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Are you thinking of starting a goldfish tank and getting a new goldfish?

Are you unsure of what type of tank to get and whether or you need a filter?

First off, in my opinion goldfish should always have some type of filtration, especially tanks smaller than 5 gallons.

Did you know smaller fish tanks are actually harder to keep clean?

This is because goldfish waste can build up much faster creating a toxic environment for your goldfish.

If this is your first goldfish I would recommend you get a tank that’s at least 20 gallons or bigger, that way you don’t have to worry about doing water changes every other day and if you happen to mismanage the tank for the first little bit, the environment of a larger tank will be a little more foregiving of your mismanagement.

If you decided to keep a goldfish because you thought it would be easy think again…

I know, I know, you see goldfish in bowls all over the place, how hard could it be?

Well, to be honest about it, goldfish are actually very messy, produce A LOT of ammonia (chemical lethal in high levels) and require regular care to keep the tank clean and the goldfish healthy.

When you keep goldfish, a Filter Is a Must, as is an air pump to keep the water as aerated as possible.

The type of goldfish you select might determine the size of tank you need. As an example;

  • A fan tail or fancy goldfish needs at least a 20 gallon tank, with an additional 10 for each other fish.
  • A common or comet goldfish needs at least 40. These fish can grow over a foot long, commons get huge and really need a pond.
  • If taken care of properly some goldfish species can live past 20 years, and grow up to 1 foot in length or larger – Yeah you might as well have children at least they leave after 18years…

Once you have selected the type of goldfish and tank size you will use you can then determine what type of filter you need. Here’s a few tips to select the filter that’s right for your goldfish;

  1. Before buying any pet it’s a good idea to learn about it. Does it have long fins that strong water will damage like the fancy tail goldfish? Does your goldfish have bubbly eyes like the black telescope goldfish that have trouble swimming in strong currents? Is your goldfish strong and fast like the common goldfish? You need to ensure your filter won’t cause any harm to your goldfish.
  2. Size of your tank – How many gallons of water do you need to clean. Every filter has a maximum amount of water it can handle. Usually the packaging will indicate how large a tank the filter can handle.
  3. Cost/Maintenance – How much do you want to spend on your filter
  4. Filter Set Up – Are you experienced or do you want something easy to set up
  5. What are the pros and cons of each type of filter; Power Filter, Canister Filter, External Filters, Air Powered Filters, Wet Dry Filters, Under Gravel Filters. See the table below.

So do goldfish need a filter? Absolutely!

If this is your first goldfish, and it sounds like it is, otherwise why would you be reading this?

A standard power filter that hangs on the back of your aquarium would be best. Here is one of the best rated power filters rated on amazon.

  The external power filters are easy to set up, clean and maintain. Cost is mid-range and they are average as far as their effectiveness. More than suitable for goldfish that need a filter.  

If you are looking for a filter that can handle large volumes then consider a cansiter filter, especially if you plan on having a large goldfish community tank.

Canister filters can handle the waste load produced by goldfish in large numbers. 

Click here to read our post on finding the right canister filter

Filter Type Cost Range Maintenance Level Effectiveness of Filtration
Mechanical Chemical Biological
Corner Filter Low Medium Low Low Low
Sponge Filter Low Low Low Low Low
Under Gravel Filter Low – Medium High Low Low Medium
Power Filter Low – Medium Low Medium Medium Low
Power Filter with Bio Wheel Low – Medium Low Medium Medium High
Canister Filter Medium High High High Medium
Canister Filter with Bio Wheel Medium High High High High
Wet/Dry Filter High Low Medium Medium High


By | 2017-04-27T09:01:21+00:00 August 26th, 2015|Goldfish Care|Comments Off on Do Goldfish Need A Filter?

About the Author:

Jack Dempsey has over 20 years of experience with freshwater aquariums, his goal is to help beginners avoid the biggest mistakes when getting started. If you find something helpful please share it on your favourite social network. If you need help with anything send Jack a question.