# Do most fish like a filter current?



## jonlong (Apr 29, 2010)

In response to a problem with ammonia that I've been having, I got a new Penguin filter with a bio-wheel. It's rated for 30 gallons, and is being used in my 20 gallon. I took out the Aqueon filter, since I don't really see how bacteria are supposed to survive when you change the filter. Anyway, my platies are spending a lot of time swimming in the current, which is stronger than before. The other fish don't seem bothered by it, and there are plenty of spaces that are current-free. But in your experience, do fish typically like currents? Are there any that are adverse to it?


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## Meenu (May 1, 2010)

Many fish play in the current. I think you are fine. (Bettas and a few others don't care for the movement, though.)

As far as filtration, in my opinion, the rating doesn't matter much. You should be looking at the flow rate. For example, since you have a HOB filter, 10x flow rate is perfect for you (20 gallons times 10 equals 200 gallons per hour desired flow rate). The Penguin 200 is perfect filtration for your tank, but for a 30g, it would actually not be enough if you are fully- or over-stocked.


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## Grimmjow (Jul 22, 2009)

I one of my tanks i have a bunch of guppies and a betta and the betta hates it but the guppies will actually line up in front of the filter and swim into it, in the tank below it i have tetras and a betta and none of them like the current.


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## Byron (Mar 7, 2009)

Welcome to Tropical Fish Keeping.

Filtration should be suited to the fish in the aquarium. As you and others have noted, different fish have different "preferences" with respect to water flow, and one way to ensure a successful aquarium community is to have fish with similar preferences to this as with other aspects.

The reason for a fish's preference comes from its natural habitat; it has evolved over thousands if not millions of years to its environment. A fish that comes from still water such as ponds and swamps, like the betta and all anabantids for example is not going to "feel" comfortable if it is constantly battling a current. And in most tanks, the fish cannot escape the current. The fact that such fish choose the quietest areas speaks volumes.

To answer your last questions, most forest fish do not like water currents. These fish come from slower-moving streams and flooded forest habitats where water movement is minimal or even non-existent by comparison to what is often the case in an aquarium. Almost all the characins (tetras, hatchetfish, pencilfish), smaller cichlids (up to an including angels and discus), gourami, rasbora are forest fish. Many catfish also fall into this category. If you check our fish profiles section, you will find references to water movement in many of them. Providing what the fish is programmed for is a key component in providing a suitable environment for a stress-free and thus healthier life.

Byron.


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## Austin (Feb 1, 2010)

Here's some pet store employee advice : Guppies don't like current.

No clue if that's accurate or not. XD But seeing the source, can't trust it.



jonlong said:


> In response to a problem with ammonia that I've been having, I got a new Penguin filter with a bio-wheel. It's rated for 30 gallons, and is being used in my 20 gallon. I took out the Aqueon filter, since I don't really see how bacteria are supposed to survive when you change the filter. *It survives on the biowheel and filter media. You are not supposed to take out the cartridges unless there is a biowheel or something else with the beneficial bacteria. If you take out the cartridge and that is all the filter media in your filter, you will end up with a mini, or full cycle. Clean the cartridge with old tank water and re-use it. Or, shove a new cartridge/filter media in there along with the old cartridge, then you can take out the old one and the new one will have at least some bacteria colony on it.
> *
> Anyway, my platies are spending a lot of time swimming in the current, which is stronger than before. The other fish don't seem bothered by it, and there are plenty of spaces that are current-free. But in your experience, do fish typically like currents? Are there any that are adverse to it?
> 
> *I've asked this same question. Not totally sure of the answer, but research where the fish comes from - if their origin has currents, or no currents, that will help you find your answer.... *


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