Do You Need a Filter in Your Fish Tank

by Aquarium Hygger Mar 05, 20220 comments

Have you ever found your fish tank covered in mystery slime and reeking of stagnant swamp water? Do you know why? And do you know what should you do? This article will tell you the secret of having a beautiful aquarium with crystal clear water. The only thing you need to do is to buy a filter for your fish tank.

What is a fish tank filter?

Fish tank filter is used for water purification and oxygen replenishment. It aims to remove water excrement and other dirt, keep water clear and full of oxygen, no harmful substances, pollution. In general, make the fish tank suitable for the growth of fish.

Why we need a fish tank filter?

As we all know, there is a lot of waste in our fish tank. In addition to the waste our pet fish produces from excrement and respiration everyday, the uneaten food or dead plants and fish also contribute to the production of waste. These waste products will accumulate in our fish tank and contaminate the water.

If we ignore the waste, our fish tank will become dirty day by day, which will influence the health and growth of our fish. In that case, the removal of the contamination becomes ever so critical.

A fish tank filter is a equipment which can help us with this problem and maintain the water quality of our fish tank.

How many methods of filtration do we know?

There are 3 common methods of filtration-mechanical filtration, biological filtration and chemical filtration.

Mechanical filtration

Mechanical filtration mainly removes the particulate material in the fish tank to make the water clear. But this kind of filtration can not remove the dissolved contaminant. Parts of the dissolved contaminant are decomposed from particulate material, so mechanical filtration can reduce the burden of filtering dissolved contaminant while removing particulate material.

The main equipment for mechanical filtration are filter cotton, filter cloth and so on. With the accumulation of contaminant, the filtration equipment will become dirty, so it is necessary to clean the filtration equipment regularly.

Biological filtration

Biological filtration uses microorganisms to eliminate the contaminant. We can use both mechanical filtration and biological filtration to remove the waste of fish, so some mechanical filtration may have the function of biological filtration.

Biological filtration aims to remove the ammonia in water. The waste of fish is not toxic, but it will release ammonia after being resolved, which is fatal to fish.

Although ammonia is a kind of gases, it can be resolved in water. With the accumulation of ammonia in water, the health of fish will be threatened. We can not use mechanical method to remove the ammonia, so we need to ask biological filtration for help.

Biological filtration offers a greatly enlarged surface area on which beneficial bacteria can develop, especially the nitrobacter. Nitrobacter is a microorganism which can break down harmful organics like ammonia.

It loves staying on the surface of biological filtration, gets ammonia in the circulating water from mechanical filtration, which can help maintain their life and clean the aquarium simultaneously.

Biological filtration can be used for a long time, there is no need to change clean it regularly.

Chemical filtration

Chemical filtration is mainly used to resolve the chemicals in water. These chemicals are generally non-toxic, but it will influence the color and hardness of water, so we must remove them.

We don’ t use chemical filtration unless in some special occasion, such as the water has changed because of the accumulation of chemical, which has great influence on the aesthetic of the aquarium.

Chemical filtration will lose efficacy after using for some time, so we must change it regularly.

How many types of filtration can we choose?

Box filter

Also called corner filter or internal filter, it is the first aquarium filter avaliable for home aquarium. It can provide mechanical filtration, biological filtration and chemical filtration and can be loaded with a variety of filter media.

Compared with other filters, box filter is suitable for aquariums of less than 20 gallons. Box filter is inexpensive and its powerful intake flow also makes it popular for use in breeding tanks with tiny fry. But it maybe a little bit noisy because of bubbling, you can use an air stone to lower the noise.

Sponge filter

The sponge filter is installed on the power head or the tube of the air pump. Biological filtration can be formed when the bacteria grows as water forcing through it. It is suitable for tanks with tiny fry, because it can prevent fry from being sucked into the pump.

Sponge filter is cheap, easy to clean and not easy to be damaged. It’s somewhat noisy because of the bubbling, but you can put an air stone in it, which could lower the sound.

Hang-on-back filter/Power filter

Hang-on-back filter, just as its name implies, is installed on the wall with one tube plugging the water. You can put a sponge around the tube to realize a prefilter and prevent the fry or shrimp from sucked up.

The dirty water will flow into the tube and be filtered through different filter media inside the filter box and then return to the aquarium as clean water. The filter media for this fliter is variable.

It is more suitable for large tanks and it is easy to clean, set up and maintain. However, the capacity of it can not contain too much filter media and it will require more energy.

Canister filter

Canister filter is best suited for medium to large-sized tanks, usually more than 40 gallons. It is positioned outside the tank, which means they can be easily hidden behind or beneath the aquarium stand.

This kind of filter will force the water to flow through filter media rather than letting water flow naturally. Canister filter provides a lot of space for filter media, so it can realize mechanical filtration, biological filtration and chemical filtration.

Canister filter also has some disadvatges. It’s expensive and annoying. When you deicde to clean it, you will feel terrible because it is difficult to take apart for cleaning and miantenance, and it’s difficlut to restart afterward.

Fluidized bed filter

It is a very efficient biological filter that uses sand or silica chips as filter media. The mechanical filtration of it is moderately good because the media can remove some particles. The filter media provides an excellent surface area for the bacterial colonies to thrive.

Fluidized bed filter is cheap, easy to set up and maintain, you can even DIY it by yourself with plastic bottle, air stone, tube and some filter media. And the fry can freely swim around it without being sucked up.

Trickle filter

Trickle filter is usually set up above the tank with a tube plug in water. There are many trickle boxes in the filter, which you can put variety of filter media in them, such as plastic balls, strands, or floss.

The dirty water will flow to the top box with the help of a water pump, and then flow through layers of boxes that contain the filter media. Finally, the clean water will flow into the tank through the tube. The dirty water will foster large colonies of beneficial bacteria that break down wastes to realize moderately biological filtration.

But trickle filter has a big drawback that it clogs fairly easily, so you’d better use a mechanical to eliminate the problem. If you need to remove the chemicals in your tank, you can also add some relative media to realize chemical filtration.

Under gravel filter

The UGF (Under Gravel Filter) utilizes a plate filter that is placed under the substrate, and an air pump that pulls the aquarium water down through the substrate, taking the particulate matter with it.

The UGF is simple to set up, maintain and inexpensive, and it won’t take too much space and you don’t have to worry about fry sucking in. The most important is, you don’t have to worry about the power running out.

However, it also has some damaging disadvantages.

The first one is the type of fish you can keep is limited. You can’t keep fish that like digging since they will dig a hole. Then the water will flow into the hole rather than the filter and you will lose beneficial bacteria potentially.
The second one is the amount of fish waste that gets clogged under the filter.
And the last is it’s difficult to get it out, you may need to break down the entire tank.