Does a Fish Tank Need a Filter? Fishkeeping 101

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Fishkeeping offers a lot of benefits; not only does it level up the look of a space, but it also helps the person de-stress.

That said, since you’d be taking care of another living being, you will want to make sure you provide it with suitable living conditions.

For instance, one of the first questions you should ask is this: Does a fish tank need a filter?

Just like any other pet, keeping fish in an aquarium comes with its own set of responsibilities.

To get you started on the right track, we’ll talk about the basics of fishkeeping.

What Is a Fish Tank?

A fish tank or aquarium is a vivarium of any size with at least one transparent side.

In it, you can house anything from amphibians, invertebrates, marine reptiles, fish of any species, and even aquatic plants.

Often, it is made of glass or sometimes high-strength acrylic. Sizes may vary, from small glass bowls with several liters to water to gigantic public aquariums.

That said, we’re going to focus on smaller fish tanks.

Any person who owns one or looks after an aquarium is called an aquarist.

Now, to set up a tank suitable for the kind of fish you want to keep, you need a particular device to maintain its water quality.

This is where the fish tank filter comes in.

Does a Fish Tank Need a Filter?

A tank filter eliminates dirt, ammonia, and nitrite buildup in an aquarium. As a result, the water becomes safe and aerated for the fish to breathe.

In a way, the filter serves as the fish tank’s heart, ensuring the water is constantly moving and preventing stagnation.

Why is this important?

Tanks can only hold a certain amount of oxygen because the water doesn’t flow, which means no movement = no oxygen.

Also, stagnant water allows ammonia to accumulate, causing damage to fish, shrimp, and plants.

Even with a filter, however, you will still need to perform water changes regularly.

If you want a tiny tank with no filter or air stone, you should know that you can only keep a set number of fish.

Otherwise, you will end up with increased ammonia in the water because of too much fish waste.

This also means you would be depriving your pet fish of the kind of living conditions they deserve.

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How Does It Work?

The way in which air and nutrients circulate throughout the tank, giving your aquarium residents what they need to live a healthy life, all depends on moving water.

This is just one of the many roles that a tank filter plays in an aquarium build.

A good tank filter ensures the walls or panels stay perfectly clean and clear to allow you to view your fish.

Basically, it comes in three varieties: chemical, mechanical, and biological tank filters.

You can find aquarium builds that feature these three filtration types, arranging them in a series to ensure the best results.

After all, the importance of each type cannot be overstated. To give you an idea, here’s how these filters work:

Chemical Filtration

When present, mechanical filtration typically comes first and captures particles that could block the following filtration stages.

It is not a standard solution, even though it can remove ammonia and other toxic substances in certain situations. Why so?

Depending on who you ask, chemical filtration may or may not be effective. For instance, it can help get rid of fish medications after they lose their effectiveness.

On the other hand, chemical filters can also take away trace elements essential for aquatic plant growth.

Avoid it unless you have a solid justification for thinking your situation calls for it.

Biological Filters

Biological filters are often placed after the chemical filtering section.

It is what breaks down fish waste, dissolving ammonia from the water and keeping your fish safe from harm.

As an effective yet inexpensive filter, you will have no problems adding it to your setup.

Cycling the tank, which essentially means making the water safe for your fish, is made easier by biological filtration.

Mechanical Filtration

Your fish tank’s entire filtration system won’t be able to maintain good water quality by itself.

This is especially true if the tank is congested, you feed your fish too much food, and you don’t do partial water changes regularly.

In fact, you probably do at least one of these things if you frequently deal with sick or, worse, dead fish.

Mechanical filtration is added to fish tanks because it removes uneaten food, plant leaves, and other particles.

As a result, you can keep ammonia levels at safe levels.

How To Care for Tank Filters

Tank filters also require some maintenance. For example, if waste clogs a mechanical filter, it eventually dissolves into ammonia, defeating its purpose.

Like mechanical filters, a biological filter will lose its efficiency with time.

In a biofilter, water passes through a porous media that filters out bacteria. Over time, how effectively it filters will decrease, too.

As for under-gravel filters, it’s important that you routinely vacuum the substrate to keep them clean.

To do this, you will first need to remove the canister and power filters, then gently rinse them in a container of used tank water to clean them.

As you can imagine, it’s not a good idea to use tap water because it may contain chlorine, which kills bacteria—good and bad.

Which Filter to Choose for Your Tank?

Choosing the type of filter to use in your tank requires careful thought.

For instance, will the tank house breeding or exhibition fish?

A hang-on-back or canister filter is the finest choice for a display tank. Conversely, a grow-out/breeding tank will benefit from a simple sponge filter.

Another thing to consider is the fish tank’s flow rate.

The water volume that passes through the filter in an hour is measured in gallons per hour or GPH.

The filter should have a flow rate of at least four to six times the tank volume. That means a 20-gallon tank needs a filter with an 80 to 120 GPH capacity.

Hobbyists should also consider the size of the filter they plan to use for their fish tank.

Again, your tank’s water should go through the filter at least four times every hour. That makes figuring out what you need relatively simple.

Always switch to a greater flow rate when it’s close to it.

In other words, a 30-gallon tank needs a minimum flow rate of 120 gallons per hour. You should get the 150 GPH filter if the options are 100 GPH or 150 GPH.

The tank will receive the maximum filtration feasible by having the proper GPH while avoiding an excessively disruptive current.

Remember that larger aquariums need larger filters to maintain enough water circulation.

In the end, there is no secret formula for determining the filter size appropriate for an aquarium or fish tank.

Be conservative and seek advice from ratings from a particular manufacturer. Also, steer clear of over-filtering because there is such a thing as too much filtration.

The Importance of Fish Tank Filters

Does a fish tank need a filter?

It is undeniable that filters ensure the safety of your pet fish while making tank maintenance simpler.

With appropriate filtration, you can rest assured your fish will thrive in its new environment.

If you want a healthy fish tank, you need to determine the right combination and size of filters to use.

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