Choosing the Right Filtration System for Your Aquarium
Published January 29, 2008
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- By Dustin Phillips
Your filtration system is probably the most important mechanical device for your freshwater aquarium. Filtration systems are essential because they sustain a natural and healthy environment for your fish. Without a filtration system for your water, it would almost be impossible to keep tropical fish as a pet. Filtration systems are that important!
Choosing a filtration system can be a daunting task because the sheer number of options to choose from can be overwhelming and become confusing. Moreover, because of the importance your filtration system plays in the overall success of your aquarium, it is crucial to choose the right system for the specific needs of your tank. Before choosing a filtration system for your tank, it is important to understand the three different filtering processes that all filtration systems use in order to sustain life in your tank.
Mechanical Filtration – This filtration process simply removes debris and particles present in your water by passing the tank’s water through foam or some other type of spongy material which traps the debris from entering back into your tank. The foam is replaced on a regular basis to prevent back-up and to maintain the effectiveness of your filtering system
Biological Filtration – This is the most important filtration process for your aquarium. Biological filtration removes toxic waste created by fish and decaying matter by creating a bed of beneficial bacteria in your filter that breaks down harmful toxins such as ammonia and nitrites. To create this bacteria bed, your aquarium must go through a process known as the “nitrogen cycle.” To learn more about the nitrogen cycle and how it affects your tank, read RateMyFishtank.com’s article on cycling your tank (http://www.ratemyfishtank.com/articles/53). Without biological filtration, it would be extremely difficult to sustain a thriving aquarium.
Chemical Filtration – This filtration process removes dissolved wastes by flowing water through activated carbon. Activated carbon is extremely porous and when water flows by it the pours trap dissolved wastes and minerals such as phosphate. Activated carbon can also remove odors and ammonia. Chemical filtration is not required to maintain healthy fish, but it can be effective in maintaining high water quality when used in conjunction with other filtration processes. When using activated carbon, it is good to note that the carbon will also remove medications from your aquarium water. So when treating ill fish with chemical water treatments remove the chemical filter from your filtration system.
Almost all filtration systems will utilize mechanical and biological filtration processes and most of them will allow you to add a chemical filtration unit. Choosing the right filtration system for your aquarium usually depends on the size of your aquarium, the size of your budget and the specific filtration needs your fish and plants need. The following list contains most of the standard filtration systems found in pet supply stores and goes into the pros and cons of each. Take a look at your specific needs for your aquarium and use this list as a guide to choosing the right filter for you and your fish.
Corner (Box) Filters – These extremely inexpensive filters sit in a corner of your aquarium and are usually clear and boxed shaped. For their price, box filters work relatively well in small aquariums (10 gallons or less). They are not used as much as they were in the past, but they make excellent filters for hospital and breeding tanks. They operate using an air stone that pushes air through an air tube which in turn powers water through filter floss which filters your water mechanically. Over time, bacteria colonies build up on the filter which will biologically filter your water. Due to their obstructive visible presence in tanks, they are not recommended for hobbyists who desire a natural and aesthetically pleasing aquarium.
General Price Rage (for 5 – 10 gallon aquarium): $2.00 - $10.00
UGF (Under Gravel Filter) - Most UGF’s are sold in beginner aquarium kits. They are inexpensive and relatively maintenance free. They work by placing a filter “plate” under the gravel or substrate of your aquarium. An air pump then pushes water through the gravel pulling particles in your water with it. They make an excellent biological filter, but as a mechanical filter, they do tend to clog over time. To prevent clogging, it is recommended to vacuum the floor of your aquarium regularly to remove the build up of particles. This is a decent option for the beginning hobbyist who does not want to continually replace filtration components.
General Price Range (for 20 gallon aquarium): $15.00 - $35.00
Sponge Filters – Though not recommended as a main tank filtration system, sponge filters are effective and commonly used in hospital tanks and small breeding tanks that contain tiny fry. Sponge filters are simple and inexpensive units that contain an airlift tube or a powerhead that forces water through a porous sponge that collects debris and bacteria. This simple set-up makes them excellent mechanical and biological filters. Consider a sponge filter if you are setting up a quarantine tank or a tank for small fry.
General Price Range (for 20 gallon aquarium): $5.00 - $8.00
Power Filters – Powers filters are the most commonly used filtration system in the hobby today. They provide excellent mechanical, biological and chemical filtration. Power filters use a chamber that hangs on the back of the aquarium and an intake tube that is inserted into the tank. The tube sucks water through the chamber passing it through a chemical filter cartridge and then through a biological sponge before the water flows back into the tank. There are many different sized power filters available at your pet supply store that can be fitted onto tanks up to seventy-five gallons, though it is widely agreed that they work best on tanks of fifty gallons or less. Many of the more advanced power filters use a “bio-wheel” instead of a sponge to better uphold the biological bacteria in your tank. Power filters are fairly inexpensive, very easy to maintain and are a great option for most hobbyists.
General Price Range (for 20 gallon aquarium): $20.00 - $35.00
Wet/Dry (Trickle) Filters – More commonly used by saltwater enthusiasts, the wet-dry filter has become more popular with freshwater hobbyists. Wet-dry filters usually have a rectangular reservoir that is divided into two sections, the “wet-dry” compartment and the “sump” compartment. The wet/dry area maintains biological filtration as water trickles over a plastic plate into the wet/dry area. The water then flows through a baffle which usually contains an activated carbon unit before it is dispensed into the sump, where the water is delivered back into the aquarium. Wet/dry filters tend to range on the expensive side of filtration options but provide excellent biological filtration. They also help tremendously in your efforts to maintain high water quality due to the fact that they increase the dissolved oxygen levels entering into your aquarium. The wet/dry filter is a great filter for hobbyists that have a large fish population in their tank. It is important to remember that even with the increased oxygen levels, it is never recommended to overstock your tank with fish.
General Price Range (for 40 - 60 gallon aquarium): $150.00 - $200.00
Canister Filters – These powerful filters are great for larger tanks because they can filter large amounts of water quickly and offer unparalleled mechanical filtration. Canister filters also have the added benefit of being placed underneath the aquarium where it is out of site. The canister filter uses a tube to suck water from the tank into the canister where it goes through several layers of mechanical filtration. It then goes through chemical and biological filters before the water is pushed back into the tank. Canisters require more maintenance than other filters and they are more expensive than other units. However, if you have a larger tank or are trying to achieve a completely natural look in your tank, this filtration system is probably right for you.
General Price Range (for 50 - 75 gallon aquarium): $125.00 - $175.00
Due to the importance your filtration system plays in the overall performance and health of your tank, it is always good to talk with a reputable pet supply store, or more specifically your local fish dealer, about what filtration system is right for your particular aquarium. A knowledgeable salesperson should be able to answer most of your questions and will be able to help explain the maintenance requirements of the particular filter you choose. You can also check out these links for more information on choosing the filtration system that is right for your aquarium.
Animal-World’s Guide to Happy, Healthy Freshwater Aquarium – http://animal-world.com/encyclo/fresh/information/freshwater.htm
“Freshwater Aquarium Filtration” on About.com - http://freshaquarium.about.com/od/filters/Aquarium_Filtration.htm
Freshwater-Aqaurium-Fish.com’s “Freshwater Aquarium Filtration” - http://www.freshwater-aquarium-fish.com/index.php?option=com_content&task=view&id=30&Itemid=49
NewAquariumInformation.com’s “Aquarium Filtration” - http://newaquariuminformation.com/aquarium-information/aquarium-filters/aquarium-filtration.htm
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