WRR Aquatech - Filter Types

Filter Types

When you are shopping for an aquarium filter, you will come across several different filters to choose from, but how do you know which ones work, and which ones don't? Well we have several recommendations, but hopefully this additional information will help you choose the right one for your aquarium.

Power Filters
Canister Filters
Undergravel Filters

Buy a filter now!

Power Filters

One of those most popular filters used on aquariums today. These are those filters that hang off the back or side of an aquarium. They usually perform only two stages of the filtration cycle, chemical and mechanical, but lack real biological filtration. As we know biological filtration is the most important of all, because it is natural and is a very important part of the nitrogen cycle. However, most of the newer filters now, perform all three stages.

A three stage power filter usually consists of these items: A cartridge, carbon, and some type of surface or media used for bacteria to grow. The cartridge performs the mechanical and chemical filtration (when carbon is used inside the cartridge). While the biological surface performs the biological filtration. One thing to look for in biological filtration on power filters, is how is it performed? What type of surface is used? What is the proper way to maintain the filter, to not disrupt the biological filtration? Some filters used sponges, sand, or simple plastic with some kind of texture, or slots molded into them.

Which is best for biological filtration? Well there are advantages and disadvantages to all of them, here are the one's we see, or have experienced.

Wardley Sandman. This filter is not to bad, it looks really cool, but we had a few problems with the sand. Putting the sand in was one, but mainly we had a problem with the motor getting sand in it's compartment. This eventually caused the motor to burn out. It is a little bit troublesome at first, but we have heard that it has worked for other people very well, (Maybe we just had a defective one). Sand is a great media for biological filtration, as long as it works right. Although not used on WRR Aquatech Certified filtration setups, it may workout to be a great filter for your aquarium, and is VERY affordable. It is available at PetsMart.com.

Remember: You are not supposed to clean the sand or replace it, that is the point of biological filtration.

Hagen AquaClear. This filter performs biological filtration with a sponge, as well as mechanical and chemical, and uses carbon for the chemical filtration (the inserts are pictured to the right), divided into three separate compartments. It is a very power filter, however the sponge can get really dirty, and once you wash it, then you just ruined your biological filtration. Because of this you are not supposed to replace the sponges at the same time, you must do it alternatively to avoid ruining the biological filtration. We found it to be a bit more expensive to replace the inserts, and more trouble then we thought to be necessary. However the filter itself is affordable, but like we said, can become more expensive when having to buy each insert separately. This product also available at PetsMart.com.

Marineland Emperor. Our favorite filters and most affordable are the Marineland Emperor Systems. These filters offer powerful filtration as well as excellent biological filtration. Flow and filtration efficiencies unmatched by other filters in their class; as much as twice the filter cartridge capacity; additional chemical filtration capability; extra effective, spray bar-driven BIO-Wheel wet/dry biological filtration... The Emperor filtration systems truly are the future of advanced aquarium technology. There is much to say about this filter, click here for more info. This product also available at PetsMart.com.

Remember: You are not supposed to clean the Bio-wheel or replace it, that is the point of biological filtration.

Canister Filters

Canister filters are powerful and offer great filtration, as well as the ability to hide underneath your aquarium, and is great if the aquarium needs to be pushed against a wall.

They usually perform all three stages of the filtration cycle, chemical and mechanical, and biological filtration.

A three stage canister filter usually consists of these items: pad or sponge, carbon, and some type of surface or media used for bacteria to grow. The cartridge performs the mechanical and chemical filtration (when carbon is used inside the cartridge). While the biological surface performs the biological filtration. One thing to look for in biological filtration on power filters, is how is it performed? What type of surface is used? What is the proper way to maintain the filter, to not disrupt the biological filtration? Some filters used sponges, sand, or simple plastic with some kind of texture, or slots molded into them.

Which is best for biological filtration? Well there are advantages and disadvantages to all of them, here are the one's we see, or have experienced.

Marineland Magnum. These filters are powerful, but one downside is that they do not all come equipped with biological filtration. There are separate packages, one in which includes the bio-wheel, and then the one which does not, (pictured to the right), however the one with the bio-wheel included would still require you to hang something on the back of the aquarium, so kind of defeats one of the purposes of a canister filter. However it is very powerful, and still keeps your water clear, but it is not as efficient as it could be with some kind of biological filtration built in. For more information about this filter click here. This product also available at PetsMart.com.

Hagen Fluval. Very powerful, but also expensive. The Fluval offer three stage filtration, and great filtration, but can be a hassle to setup. We had a lot of trouble setting up our Fluval because it would prime. Finally after about an hour we got it working, with the help of a Fluval representative. After the first time though it seems to get easier. So don't let a little work at the beginning discourage you, it is a great filter, especially when used in combination with the Magnum. This product also available at PetsMart.com.

Undergravel Filter

An undergravel filter is simply a slotted piece of plastic (undergravel plate) that sits on the bottom of the aquarium and lets water flow between the plate and the bottom of the tank. There is a tube that is attached to this bottom piece, known as the lift tube. Gravel is placed on top of the filter, and the filter, lift tube and gravel work together to provide filtration. Undergravel filters generally perform only one stage of filtration which is biological filtration.

Water is pulled down to the bottom of the tank, through the gravel. And then the undergravel plate, then flows back up to the top through the lift tube. The water is again pulled down through the gravel. This allows beneficial bacteria to thrive on the oxygen laden water flowing through the gravel.

When using an undergravel filter you should purchase at least 1.5 pounds of gravel for each gallon your aquarium holds. If you are using a power filter or and no undergravel filter, you may use slightly less gravel. One pound of gravel per gallon in your aquarium should be enough.

Using an Air Pump with an Undergravel Filter
Water is cycled through the aquarium with either a powerhead or an air pump. With an air pump, the air is pumped through plastic or silicon airline tubing to an air stone, which is suspended in the undergravel filter lift tube. The air forced through the air stone creates uniform bubbles in the tube, which changes the air pressure in the tube. This change in air pressure creates a vacuum that pulls water up and out of the tube, thus creating the suction underneath the gravel bed. It's kind of like drinking out of a glass with a straw.

Using a Powerhead with an Undergravel Filter
Water can also be cycled using a powerhead instead of an air pump. In this case, a powerhead is placed on the top of the undergravel lift tube. It "powers" the undergravel filter by pulling the water down through the undergravel filter and up the lift tube where it is expelled onto the surface of the water. A powerhead can be used to increase the water circulation and improve the biological filtration of an underground filter. Gravel helps in filtration in several different ways. It collects loose debris as it's pulled down through the gravel and it provides a breeding ground for beneficial bacteria in an aquarium since there's so much surface area for bacteria to grow on.

Keep in mind that too much gravel will cause a problem with the water flow through the undergravel filter and can result in anaerobic bacteria, which is actually detrimental to the environment. An insufficient amount of gravel will not create a proper biological filtration bed. There needs to be enough gravel for the good bacteria to grow, and to make enough of a "filter" for waste to settle in.

Things that are annoying about undergravel filters can be the noise from the air pumps, making bubbles in the water, (this varies on the undergravel filter). Also if a plate comes up, or you have to move an aquarium, you will have a lot of 'stuff' come up from underneath the plates. Finally, the algae that grows inside the tubes. An extra step for maintenance. To remove the algae from the undergravel lift tubes, a lift tube algae scrubber is shaped to work best. A standard bottle scrubber works also, but it must be used exclusively for the aquarium.

These products also available at PetsMart.com.
Click here to view our recommended filters!

E-mail this page to a friend!