This is a follow up of a previous post titled “What Are Undergravel Fish Tank Filters?“.

The one thing that with guarantee healthy and vibrant fish above everything else is crystal clear water in your aquarium. And only fish tank filters are able to do this for you. Fish tank filters are the most important tool in an aquarium and together with a fish tank heater, forms a perfect system that is capable of providing your fish with a similar environment from where they originated.

One filter that has stood the test of time is the undergravel fish tank filters. Though it is mostly used by beginners to fish breeding, it is able to provide water filtration that is reliable and efficient comparable to any other filter.

Undergravel Fish Tank Filters

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The filter functions by drawing water through a layer of gravel. The gravel rests on a slightly raised platform away from the base of the tank. This creates a division between the unfiltered water at the top and a layer of clean water at the bottom, with the gravel acting as a filter. It performs mechanical filtration by trapping large debris, food excess and waste and beneficial bacteria in the gravel layer also perform biological filtration.

Undergravel Fish Tank Filters Are Great

Here are 8 reasons why I consider undergravel fish tank filters to be among the best types of filters on sale today.

Reason #1: It Regulates Temperature

The undergravel filter sucks in water from the bottom of the fish tank and pumps it back from the top. This will mix the water up continuosly, as long as you do not turn off the filter. This circulation of water causes every area of the fish tank to experience the same temperature.  Because of this water circulation, every part of the aquarium maintains the same temperature. Additionally, you could also place your fish tank filters beside the lift tubes, which will warm the water as it rises and provide excellent temperature balance in your fish tank.

Reason #2: Water Aeration

As the filtered water rises from the bottom through the lift tubes, it will come in contact with outside air. This aerates the water even better than the bubbles in the tank could.

Reason #3: Excellent Mechanical Filtration

In this system it is the gravel that acts as the filter media, trapping large debris, food waste and excess perfectly.

Reason #4: A Good Biological Filter

When you have allowed the gravel to age, usually within six weeks without help, beneficial bacteria will colonizes the gravel. These Organisms reduce organic proteins into nitrate which can simply be discarded each time you change the tank water. The nitrate is also a substance consumed by aquatic plant life.

Reason #5: It Is Capable Of Chemical Filtration

This is one factor ignored by most people, that undergravel filters are capable of being fit with cartridges that perform chemical filtration. Inside these cartridges usually are activated carbon that helps remove heavy metal, complex proteins, odor, color and even chemical treatment.

Reason #6: A Bigger Capacity For Waste

Because it is the entire area of gravel at the base of the tank that actually filters the water, undergravel fish tank filters can hold the most waste before it needs to be cleaned.

Reason #7: Easy To Maintain

Over time, the gravel will begin to accumulate a layer of muck thatneeds to be cleaned. if it isn’t then it will begin to choke the filtration system by not allowing water to pass through. How do you clean it? By simplying vacuuming up the muck. A simple method of doing this is by using a rubber hose as a siphon to suck up the muck when you plan to do your water change.

Reason #8: Inexpensive

Isn’t that really the main draw for most of us? Buying an entire set is usually cheaper than other reliable filtration systems. The filter media is the gravel and never needs to be replaced. The parts are quite sturdy and even if you need to replace a part, they are cheap.

Undergravel Fish Tank Filters (Click for specs)

There you go. 8 reasons to convince you how good the undergravel fish tank filters are.

This is a follow up from my earlier post “Choosing The Right Fish Tank Filters“.

In general undergravel fish tank filters are a type of filter where water flows through a layer of gravel which acts as the primary filtration media. The undergravel fish tank filters system consists of a plastic grate which is placed at the bottom of the tank, tubes that direct the water through the filter and a power head or pump.

Undergravel Fish Tank Filters

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The plastic grate lies at the base of the tank. A layer of gravel is placed on top of the plastic grate. This separates the water above the gravel from a layer of clean water below the plastic grate. Water is drawn through the gravel layer, which acts as a biological and mechanical filter. The flow of water through the gravel is achieved with the pump which has an inlet below the plastic grate, sucking the water below through plastic tubes that will then spill the clean filtered water from the top of the tank. As the tubes suck out the water from below the plastic grate, this forces the water above to be drawn through the gravel layer where, through mechanical filtration, sediments, excess food and waste is trapped. The gravel layer also performs basic biological filtration by trapping bacteria. The water that results from this filtration will be clean and will follow the cycle, flowing through the tubes and to the top of the tank.

Undergravel Fish Tank Filters Maintenance

Because your filter media is the gravel, you will never have to replace it. However, as the particles are trapped by the gravel it will need to be cleaned. The frequency of cleaning that you need to do varies, depending on how many fish you have in the tank and how frequent you feed the fish. If you have a large tank, it would be easier to use an aquarium vacuum to remove the sediments from the top layer of the gravel. If your tank is small, you may as well just wash the gravel when it starts to get slimy. As the sediments build up above the gravel it will eventually block the flow of water through. Sediments would also be forced through due to the suction of the pumps. This will create a lower water quality in the tank. So it is important to clean the gravel as the sediments build up.

Different Brands Of Undergravel Fish Tank Filters (Click For Specs)

Undergravel fish tank filters have received some bad press from people who claim that it does not provide sufficient filtration as well as a build up of waste at the bottom of the tank. But undergravel filters are good for beginner fish tanks that do not contain many fish, is not too large and the fish you are breeding are not overly sensitive. It is relatively cheap compared to canister filters and power filters. It requires very little maintenance and is very easy to clean. Though does not provide chemical filtration, if what you have is just a basic fish tank than this would be a good fish tank filters to start out with.

Continues in the next post: Benefits Of Canister Fish Tank Filters