do goldfish need a filter

🥇 Do goldfish need a filter ? | The facts and 5 Best filters you should consider.

If you have been wondering, ‘do goldfish need a filter?’, the answer is yes, Goldfish do need a filter. For a goldfish to live a long and healthy life, a filter is very necessary.  These are fish that need to be handled with a lot of care, and they most definitely are pets that do not require enormous resources to maintain them, but they do have some requirements that need to be met.

The food your goldfish eats is eventually dumped in the water as waste which pollutes the water. This being a continuous cycle it can quickly pollute the water to a level at which it becomes toxic to your fish.

If one needs to take proper care of their pet goldfish, it is highly imperative that they also invest in a good filter so that the fish can get the utmost love and care that they deserve.

There are canister filters for traditional tanks, goldfish bowls and decoration containers. It’s always good to have one in your tank. Goldfish eat a lot and hence they produce a lot of waste and greatly pollute the tank.

Surprisingly, goldfish don’t have a stomach. Instead, they have intestines twice the length of their body. This gives them a difficult time in digesting proteins. They end up releasing the proteins before they are fully digested.

Goldfish also remove their waste through the gills and ventricles. Without a filter, the tanks will definitely become toxic to the fish, which may foster disease or even lead to death.

How long can goldfish live without a filter?

The lifespan of goldfish without a filter is not determined by the size of the bowl. Even if you put your fish in a large bowl and do proper maintenance and care, this probably won’t increase their lifespan. Fish without a filter can live approximately 2 to 3 years in a small bowl.

Goldfish in filtered water lives up to 40 years. The great gap in years proves why goldfish need a filter.

do goldfish need a filter


Filtration is done in three ways:

1 Mechanical Filtration– It involves the use of fine material. In this case, it is usually a 32 sponge or a piece of cloth made of polyester. The sponge and polyester cloth prevents solid particles from entering the filtration areas. It also helps to keep the water clean.

The challenge with mechanical filtration is that the filter needs to be cleaned regularly; after one or two weeks. Letting the solid particles to pile up causes levels of nitrates in the water to get too high. This may make your fish sick.

2 Biological filtration– This filtration provides room for the growth of good bacteria which reduces the toxins produced by your fish. The bacteria keep the fish safe when the water changes. Failure to use this filtration type results in ammonia and nitrate spiking which are poisonous to your fish.

3 Chemical filtration- It uses natural elements to purify the water through the process known as detoxification. This process detoxifies the toxic chemicals as they pass through it.

Chemical filtration is recommended for use when adding small fish to the tank or bowl where either ammonia or nitrites levels can be concentrated. The method used in this filtration is by use of charcoal which removes contaminants in the water that may cause brownish discoloration.


The five best filters for the goldfish

Currently there is a wide range of filter options available in the market today which are ideal for gold fish. These filters have different technologies and media, which is a crucial factor when it comes to performance and cost. Some filters will be more efficient at aerating the tank while some are more efficient in filtering debris from the water.

When selecting a filter for your tank, it is best to consider one that that causes the least disturbance to the water. Fish are accustomed to still water and not swimming against currents. A good filter should have the capacity to keep ammonia nitrate levels in the tank low.

A good filter will maximize the stocking capacity of your tank and achieve the highest quality of water.

Since goldfish’ health is far better than regular cleaning of the filter, canister filters can be used. To get the best filter, find out the one with large volume of filter media than the Walmart special with small blue filter cartridges. In other words, go for Aquaclear filter.

Finding out the filter size is as well viable. A better filter should at least have 4 times cycle per hour. For instance, with a 55-gallon tank go for a filter rated at 220 gallons hourly.

Here are some of the best filters for your goldfish;

  1. Fluval Power filter



It is effective in reduction of ammonia and nitrites. The wet or dry trickle is useful in maximization of the oxygen being exchanged and also allows the removal of nitrates.

Fluval Power filter is cheap, convenient and inconspicuous. It accepts all of the three filtration processes; chemical, biological and mechanical filtrations.

The trickle media enables the exposure of media to oxygen and water at the same time to ease its work with the submerged media.

Fluval filter reduces the time between filter cleanings and prevent dirt building up in the filtration media. It’s this dirt which may make your fish sick.

This filter fits up to 30,50 and 70 gallon tanks.


  • Easy mode of operation
  • Easy to maintain
  • Capable of performing all the three filtration processes
  • Maximizes on the oxygen content of your water


  • Sometimes water drawn out is much as water being brought in

2 Penn Plax Cascade Canister filter



This is the most powerful filter. It is large with enough space. In addition, it is able able to fit any tank ranging from 30 to 200 gallons. The filter is effective for highly stocked Aquariums. Water runs from the aquarium down to the underneath filter and again back into the aquarium.

Large rooms in the tank gives your fish enough room for swimming. Penn Plax is affordable and reduces nitrates in the aquarium. Sponge pre-filter prevents waste from piling up underneath the water.

Penn Plax has to be kept clean by being washed after every 6 months. Within one or two weeks, just wring the sponge out.


  • Incorporated with activated carbon cartridge to remove harmful toxins
  • An affordable filter
  • An internal sponge to promote settlement of good bacteria
  • Polyfiber floss cartridge filters out floating particles


  • Weak motor

3 EShopps wet/dry sump filter system


These filters get their name in their design to maximize biological filtration. This is achieved by keeping the filter media out or above the water. The principle behind this is that the bacteria need oxygen to effectively control the ammonia and nitrates levels in the water. Putting the media submerged will limit the amount of oxygen they get.

It’s also known as wet-dry filter, trickle filter or sump. It has got powerful biological filtration which increases stocking density potential. Goldfish keepers prefer using this filter for healthy fish than buying too many filters to perform the filtration.

Wet-dry filter types are to mean an above the tank and under the tank setup. In above the tank set up, water is pumped from the tank into the tray above the tank and trickles over different layers of filtration media.

The sizes of sumps are: 10-75 gallons, 75-125 gallons, 125-225 gallons and up to 400 gallons.


  • Maximizes on supply of oxygen to the bacteria hence effective filtration
  • Available for all sizes of tanks
  • Highly unlikely to be clogged


  • It only drain to the level of overflow
  • The noise may sometimes be unpleasant

4 Penn Plax Undergravel filter


This is a reliable option for keeping water in your tank clean and healthy with minimum setup effort and general maintenance. It has four plates and 1-inch adjustable lift tubes that have been concealed to maintain the high aesthetic standards of your tank.

These are modern which are very ideal filtering a goldfish tank. The filter is cheap, it doesn’t stress the fish with excess current and has a large surface area. Large surface area supports the growth of important bacteria unlike other filters.

It’s a great choice to use in both freshwater and saltwater tank. If you own a 5 to 55 gallon tank, then you should definitely purchase this filter.


  • Best value for your money
  • Great for large tanks
  • Easy to set up and maintain


  • Tube pieces are to some degree thin and weak

5 Hikari Bacto-surge High Density Sponge filter



Buyers prefer this filter because it’s long-lasting Sponge doesn’t disintegrate quickly when you squeeze. It is also the best for the small and delicate fish.

Since it has a large surface area, sponge filters pull water through the sponge using an air pump. Hikari filters reduce nitrates in the water, it’s simple and doesn’t require regular cleaning. The filter is popular because it has high water aeration.

This filter is ideal for both freshwater and marine applications.


  • Long-lasting sponge
  • The highly porous sponge provides larger surface for bacterial action
  • Easy to clean and maintain


  • The filtration sponge wears off with time



  • If you are not in position to add a filter to your tank, then you should consider implementing this options:
  • Keep you fish tank /bowl away from direct sunlight which encourages the growth of algae and accelerates the  decomposition of debris in your thee water.
  • Adding live plants in  you tank will certainly help improve the quality of air in the tank by absorbing Co2 from the water.
  • Consider Completely changing the water in your tank at least once a week