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Is a sponge filter enough for goldfish? (Answered)

If you are wondering, is a sponge filter good enough to filter a goldfish tank then you are in the right place. 

In this article, I’m going to answer the same question.

Goldfish produce a lot of waste so only a sponge filter is not enough to filter a goldfish tank. You’ll need either a canister filter or a powerful HOB filter with a sponge filter to keep your goldfish tank clean.

Now let’s dive a bit deep into the topic. And I’ll also tell you how to set up filtration for your goldfish tank to keep your goldfish tank clean.

Keep reading…

Is a sponge filter enough for goldfish? (Answered)

Why a sponge filter is not enough for goldfish?

Goldfish image with text "Why a sponge filter is not enough for goldfish?"

Goldfish can grow pretty fast. And they can grow pretty large. Common goldfish can grow as large as 14 inches!

Besides, goldfish are not very good at digesting food. That’s why they produce a lot of waste

Though sponge filter provides good biological filtration it is not enough to filter all the waste that goldfish produces in the tank.

That being said, a sponge filter may be sufficient to handle waste produced by a small goldfish. 

However, as I said earlier, goldfish can grow pretty fast. So very soon you’ll need to add either another filter or set up a canister filter to keep your goldfish tank clean.

Are Goldfish Good for Beginners? (Answered)

How much filtration do goldfish need?

Goldfish image with text "How much filtration do goldfish need?"

Goldfish are very messy fish you’ll need more filtration in a goldfish tank compared to other fish. 

First of all, you’ll need to house your goldfish in a large enough tank.

As goldfish produce a lot of water and they grow very large and fast, ideally, you should keep a single goldfish in a 20-gallon tank. And an additional 10 gallons for each fish you add in the tank.

For example.., if you want to keep three goldfish then you should keep them in at least a 40-gallon tank. 

Keeping goldfish in a larger tank is important to dilute the waste produced by the goldfish in the tank.

Now let’s talk about the filtration for the tank.

When it comes to filtration for a goldfish tank a general rule of thumb to follow the filter should be able to filter water at least 5 times the volume of the fish tank.

For example.., if you have a 40-gallon fish tank then you should have a filter or combination of filters that can filter at least 200 gallons of water per hour.

Now following the “5 times the volume of the fish tank” is a good rule of thumb to follow. 

However, remember it is the minimum filtration that a goldfish tank needs. 

Ideally, you should have more filtration in your goldfish tank. You can have filtration as much as 10 times the volume of your goldfish tank.

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What kind of filter is best for goldfish? (Examples)

Goldfish image with text "What kind of filter is best for goldfish? (Examples)"

Compared to other fish, goldfish are very messy fish. They produce a lot of water in the tank. 

So to clear the waste and keep your goldfish tank clean, you’ll need a filter or a combination of filters that can filter at least five times the volume of your goldfish tank. Ideally, you should have a filtration system that can filter ten times the volume of your aquarium water.

Filtration system for a 30 gallon tank

I consider 30 gallon as a minimum tank requirement for a goldfish tank.

This is because goldfish are social fish so ideally, you should have at least two goldfish in your tank

And to keep two goldfish you’ll need at least a 30 gallon tank. 

Now talking about filtration for a 30 gallon goldfish tank, ideally, you’ll need 300 gallons of water circulation per hour. 

For which you can either use a large canister filter or you can use a combination of a small canister filter and a Hand On Back filter. You may also have two hang of the back filter to filter your 30 gallon goldfish tank.

If you want to use a single larger canister filter then you can go for Fluval 07 Series Performance Canister Filter (307) (link to Amazon).

This filter can circulate 303 US gallons of water per hour and it is very energy efficient as well.

You can check it out at Amazon here.

If you are going for a combination of a small canister filter and a HOB filter then you can get-  

  1. Fluval 07 Series Performance Canister Filter (107) (link to Amazon)- It is a smaller version for the canister filter I’ve mentioned above. And it can circulator 145 US gallons water per hour 
  2. AquaClear 30 (link to Amazon)- its a HOB filter and it can circulate 150 US gallons water per hour 

If you want to have two HOB filters then you can get two AquaClear 30 HOB filters. Each filter can circulator 150 gallons of water so in total they can circulator 300 gallons of water which is enough for a goldfish tank.

Whether you should have a large canister filter or you should have a combination of filters it doesn’t matter.

The only benefit I can see for having a combination of filters is that, if for any reason one of the filters failed then you’ll at least have another filter running to save your fish.

Filtration system for a 50 gallon tank

For a 50 gallon goldfish tank, ideally, you’ll need a filtration system that is capable enough to circulate 500 gallons of water per hour

To filter the tank you can either get a large canister filter or you can have a combination of filters. 

If you only want to have a large canister filter for your 50 gallon goldfish tank then you can go for the large version of the Polar Aurora canister filter (link to Amazon).

It can circulate 500 gallons of water per hour. You can check it out at Amazon here.

If you want to have a combination of filters then you can get a small size canister filter and hob filter 

For example, you can get – 

  1. Fluval 07 Series Performance Canister Filter (307) (link to Amazon). It can circulate 303 gallons of water per hour.
  2. AquaClear 50 HOB filter (link to Amazon). It can circulate 200 gallons water per hour 

You can also have two hang of the back filters to filter your 50 gallon goldfish tank.

For example, you can have two AquaClear 70 HOB filters. Each filter can circulate 300 gallons of water so in total, they can circulate 600 gallons of water which is more than enough for keeping your goldfish tank clean.

FAQs

Goldfish image with text "faq"

Can you over-filter a goldfish tank?

You can’t over-filter a goldfish tank. Goldfish are very messy fish so generally, you’ll need more filtration for a goldfish tank.

Ideally, your goldfish tank should be able to circulate water about ten times the volume of your goldfish tank.

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Is it OK to have 2 filters in a fish tank?

It is totally fine to have two filters in a fish tank. The benefit of having two filters is that if for any reason one of the filters failed then you’ll have at least one filter working to save your fish and keep the aquarium clean.

How Long Do Goldfish Live without Food? (Answer Might Surprise You)

What is the best filter for black moor goldfish?

If you are looking for a hang on the back filter then you can go for the AquaClear HOB filter. Or if you are looking for a canister filter then you can go for Fluval 07 Series Performance Canister Filter for your Black moor goldfish tank. These filters have different variants according to their filtration capacity. So you can choose the filter according to the size of your goldfish tank.

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What is the best hang on back filter for goldfish

AquaClear is the best hang on back filter for your goldfish tank. This filter comes in different variants that can filter a fish tank from 20 gallon tank 110 gallon tank.

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What is the best canister filter for goldfish tank?

Depending on your goldfish tank size you can go for a Fluval 07 Series Performance Canister Filter or a Polar Aurora canister filter.

For smaller tanks up to 30-40 gallons, Fluval 07 Series Performance Canister Filter is a good choice. If you have a larger tank of up to 50 gallons then you can go for the Polar Aurora canister filter.

Conclusion

Sponge filter has a very small filtration capacity so it’s not enough for a messy fish like goldfish. For a goldfish tank, you’ll need either a canister filter or a large HOB filter.

I hope you found the article helpful.

If you do please share it.

Happy fishkeeping!

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