10. Choosing the Right Filter

10. Choosing the Right Filter

• Undergravel	• Hanging/Box	• Internal
• Fluid Bead	• Fluid Bed	• Pleat
• Canister	• Trickle	• Protein Skimmers
• UV Sterilizer	• Ozonizers

The single most important factor in successful fish keeping is water quality. Fish and other livestock, including invertebrates and plants, are captives in a tank environment so it is imperative that keepers accept the responsibility to ensure that their environment is clean, healthy and free of disease and disease-causing situations. Most new keepers, and some seasoned keepers as well, are unaware of how quickly ammonia can pollute an entire tank and kill fish within hours. Everything can look great but within a short span of time, everything is dead.

With the wealth of information, equipment and products available today, fish keeping should be easier and more successful than ever, but, unfortunately, too often keepers ignore the basic rules and face problems. Equipment and products may come and go, but the science of maintaining a clean, disease-free environment never changes.

Filtration is critical to water quality. A filter is a compact unit packed full of high surface area media where millions of beneficial organisms flourish. As the aquarium water, filled with fish waste and other debris, passes through the filter these organisms 'consume' the wastes, thus eliminating the pollutants that could eventually kill the fish. The market is saturated with filters of all types and choosing which type is right for you is an important decision. The first rule of fish keeping is - understand the Nitrogen Cycle. The second rule is - buy the best filter you can afford. Every single time your tank has water quality problems, the solutions are associated with these two rules.

Filter Types and Ratings

The filters types below are described and are given a rating system from 1-5, 5 being highest based on the criteria listed below. N/A means that feature is not applicable to that filter type.

Chemical Filtration - space to accommodate carbon, resins, phosphate removers, etc.
Mechanical Filtration - capable of removing actual particulate material
Biological Filtration - active surfaces for reducing ammonia and nitrite
Ease of cleaning
Economical to use
Packing Life - time between cleanings and media replacement
Aeration - capable of oxygenating the tank water
Ease of setup

• Undergravel Filters

The old standby. People either love them or hate them. Undergravel filters have huge surface areas for biological filtration and can be operated with either airstones and an air pump or powerheads. When using powerheads, remember to use the aeration feature on powerheads or an airstone. These systems are occasionally the only filters that will fit the application. The down side is without frequent gravel cleaning via water changes, undergravel filters are a problem waiting to happen. Always use additional filtration, whenever possible.

Rating

Chemical Filtration

Mechanical Filtration

Biological Filtration

Ease of cleaning

Economical to use

Packing Life

Aeration

Ease of setup

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• Hanging/Box Filters

Probably the most sold type of filter. Although easy to both install and maintain, these filters require frequent cleaning and pad/sponge replacement. This is, however, a fairly easy task. Remember, these units hold the aquarium away from the wall 3-5 inches. For better water quality, opt for multiple box filters instead of bells and whistles. If one filter goes down, there is a backup. Never change both pads in a double padded filter or both filters in a dual box filter setup at the same time when cleaning. Alternating the media replacement preserves important bacteria. Some filters have room for additional bio media which should be used. Some have aeration features - moving surface water also aerates but remember, heavily loaded systems benefit from a decoratively placed airstone.
Prefilters, like the Filter Max II Prefilter, fit most models and increase all aspects of filtration for these units while preventing small fish and invertebrates from being injured. Rinse these filters at the
first sign of reduced flow. Multiple filters can be hooked together if flow is restricted or cleaning is required too often.

Rating

Chemical Filtration

Mechanical Filtration

Biological Filtration

Ease of cleaning

Economical to use

Packing Life

Aeration

Ease of setup

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• Internal Filters

Many filters fall into this category. They include internal sponge, powered internal, and internal box or canister filters - air powered and motor powered. Breeders love them. They are easy, low cost, low hassle filters. They all aerate and biologically filter. The old fashioned, floss-filled internal air driven box or canister filter is great for breeding tanks, small tanks or for quarantine tanks. Internal filters can be packed with a range of filter media for biological, chemical or mechanical filtration depending on the application. Because they operate by forced air, they both aerate and filter the water. If a larger tank is having problems, add an internal filter filled with high quality carbon and floss. The disadvantage of filters in this class is size - they are simply too small to handle much fish load, must be hidden and take up floor space.

Rating

Chemical Filtration

Mechanical Filtration

Biological Filtration

Ease of cleaning

Economical to use

Packing Life

Aeration

Ease of setup

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• Fluid Bead

These filters are designed for the higher demands of koi ponds. They are good for knocking down debris that can be easily backlflushed out of the system. On extremely heavy loaded ponds use a fluid bead in combination with a trickle filter. Sand filters, to which modifications are made to the media, are also be used for this category. See The Ultimate Koi Pond for more details on plumbing these filters into a koi system.

Rating

Chemical Filtration

N/A

Mechanical Filtration

Biological Filtration

Ease of cleaning

Economical to use

Packing Life

Aeration

Ease of setup

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• Fluid Bed

These units have been around for many years and have come and gone in popularity. Considered by some to be the ultimate biological filtration, they are often hard to control and do not oxygenate the water. They should only be used with some form of aeration. Fluid beds are best used on systems that are extremely heavily loaded and have limitations on space for larger filters or to expand the capacity of existing systems.

Rating

Chemical Filtration

N/A

Mechanical Filtration

N/A

Biological Filtration

Ease of cleaning

Economical to use

Packing Life

Aeration

Ease of setup

• Pleat Filter

Pleat filters are, with out question, the best form of mechanical filtration. If removing small particles prior to a UV sterilizer, carbon, or heater chamber is your goal, these are the type of filter you are looking for. Pleat filters, however, do come with a price. Most of the filters in this category require advanced installation abilities and are best suited for commercial or large scale use. They also are best used with some form of biological filtration and additional aeration. Large sand filters, while not actually pleat filters, are included here. When packed with sand, they are used for large scale mechanical filtration and they also have biological capabilities. Consider them also with modified packing for koi ponds - see The Ultimate Koi Pond.

Rating

Chemical Filtration

N/A

Mechanical Filtration

Biological Filtration

Ease of cleaning

Economical to use

Packing Life

Aeration

Ease of setup

• Canister Filters

Canister filters are quiet running filters with high biological capacity and should be considered second choice to trickle filters. Canister filters have both pros and cons. The better designed units have good chemical filtration because no water by-passes the media. Canisters are also ideal for planted freshwater systems or when trickle filters are simply too large for the application. Canister filters provide long service life if packed properly with quality media and are economical to operate compared to box filters. Remember, these filters are closed systems and usually have lower flow rates. Use a small air pump and a decoratively placed airstone in aquariums without live plants or in saltwater systems without protein skimmers. Air pumps increase oxygen levels and act as a fail-safe in the event of a filter failure. Choose a canister filter one size larger than manufacturers recommend for heavily loaded systems or for saltwater. Larger filters are more efficient and have higher flow rates. Stay away from filters that use small internal baskets for media. Better units have either large internal baskets or trays and can be completely packed using 99% of their space for media.

Rating

Chemical Filtration

Mechanical Filtration

Biological Filtration

Ease of cleaning

Economical to use

Packing Life

Aeration

View All

• Trickle Filters

This is the most important decision keepers make. Saving a few dollars at this stage can mean countless dollars in fish losses. Underfiltered tanks cause problems again and again and make fish keeping a headache instead of a pleasurable, exciting hobby. Trickle filters are the best choice for tanks above 30 gallons. Good mechanical and biological filtration maintains robust oxygen levels and keeps harmful fish waste and other decaying debris from polluting the water and killing fish. Trickle filters, because of their size and expanded biological surface area, perform these tasks better than any other form of filtration and should always be considered the first choice. Trickle filters are more reliable and easier to maintain. Since there are no costly cartridges to replace, trickle filters are also more cost effective to operate.

Rating

Chemical Filtration

Mechanical Filtration

Biological Filtration

Ease of cleaning

Economical to use

Packing Life

Aeration

Ease of setup

View All

• Protein Skimmers

Protein skimmers remove proteins and waste aiding in algae and water quality control while lessening the need for carbon use in fish only systems. They are not needed for aeration in a system with a quality trickle filter. Skimmers help in phosphate removal and should be considered mandatory to all “reef” setups. Some of the “Mud Type” systems do not call for them, however, they could be added if needed. Skimmers increase the efficiency of any system. Remember, all skimmers require cleaning and regular checking.

Rating

Chemical Filtration

Mechanical Filtration

Biological Filtration

N/A

Ease of cleaning

Economical to use

Packing Life

N/A

Aeration

Ease of setup

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• Ultraviolet Sterilizers

Technically not filters, UV sterilizers certainly affect water quality. These units kill unwanted bacteria and parasitic pathogens thus reducing chances of disease outbreaks or spreading. They also help clear bacterial blooms that sometimes cause white, cloudy water. No store central systems go without sterilizers and that speaks for itself. These, like protein skimmers, can be added at any time. Some “reef” keepers install them in case a problem arises. Sterilizers can be turned on when adding new fish or as needed.

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• Ozonizers

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