Different Types Of Filters

[dmarie04]

What is the difference between all of the different filters? I usually just use the filters that come with my tanks (hang on the back filters, I guess they are called), but I see people mention sponge filters, under gravel filters, canister filters and corner filters. What's the difference? is one better than the others? How do they all work?

 

[thegnu]

sponge filters are normally just a sponge attached to a plastic tube stuck on the inside of the tank with a powerhead or an air pump to circulate the water through the sponge to trap debris
UGF are plastic filter plates that are laid on the inside floor of the tank covered with gravel with two clear plastic tubes one at each end. inside the tubes you insert an airline with an airstone (diffuser) to create lots of small bubbles run by an air pump or powerhead. the idea of this air coming up the tubes (uplifts) brings with it water creating a current inside the tank continually going down and your gravel filters out the debris and the bacteria in the gravel converts the toxic wastes into less harmful ones.the corner or internal filter is obviously inside the tank with filter media inside to trap the debris and can be emptied, run by a more powerful motor (pump) with an impeller.
canister filters are like an external version of the last one (internal) and the best.
the first one is cheapest and they all go up in price and all do a better job than the one before

 

[Bloo]

Hope this helps you

Here's my take on filters...

Undergravel filters

Good: Cheap to set up. Support lots of bacteria, and if built properly, very effective. Low maintenance (stir gravel before each water change). Reliable (not much to go wrong). Works in any size aquarium and with any size fish (though not necessarily the ideal for, say, red tail catfish).
Bad: Plants with roots don't like them. Limits your choice of substrates. Dead areas under rocks/bogwood. Solid wastes aren't "sucked away", they stay in the tank, which is unsightly. Once a year the filter plate will need cleaning, which involves emptying the tank.

Internal air-powered filters

Good: Cheap. Work well with fry and other small fish. Very easy to clean.
Bad: Limited flow of water, so not much use with messy fish or in big tanks.

Internal canister filters
Good: Convenient. Easy to maintain. Different sizes suitable for different sized tanks.
Bad: Expensive for what they do (poor water turnover per unit money). Lack of water flow limits value in big tanks.

External canister filters
Good: Good value (water turnover per unit money). High pressure water flow, so good for big tanks/messy fish.
Bad: A dog to maintain. Leaks are disastrous. Closed chamber makes them very sensitive to water flow stoppages (lack of oxygen kills bacteria).

External hang-on filters
Good: Open design lets in oxygen for good biological filtration. Various sizes available for different sized tanks. Easy to maintain.
Bad: Fairly expensive for what they do (water turnover per unit money). Limited flow of water so not good for big tanks/messy fish.

These are the basic filter types, anyway. So what you need to do is rank what's important for you. If you have big fish, then external canisters and to a lesser degree undergravels are the best. If you have small fish in a small tank, then an air-powered sponge or an internal canister might be suitable. If you want to save money, then avoid internal and hang-on filters, and look at undergravels and external canisters. If you want something easy to look after, then air-powered and internal canisters have the edge. If you want plants, avoid undergravels. And so on.

Cheers,

Neale

This might help or this too

Edit: This one is very good too

 

[Tolak]

Determining the best filter or combination of filters depends on the fish you keep, the size of your tank or tanks, and if you plan on or are actively breeding.

Let’s start with the air driven filters. Sponge filters are great for fry tanks; they are a low flow/low turbulence filter if you use just a little air. They are a great bio filter, if you increase the airflow or add a powerhead they aren’t bad for mechanical filtration.

Box filters are another air driven filter; you have a wider range of media options with these. With coarse sponges & floss they are a good mechanical filter, provided once again you have enough air. Fill with bio media or just plain gravel, slow down the air, and they are a good bio filter. You can add carbon, peat, or whatever to these.

Under gravel filters are an old mainstay in the hobby, and are what many older aquarists started out with. They provide excellent bio filtration due to the amount of bio media, but are only so-so for mechanical filtration. Once again, adding a powerhead increases flow and mechanical filtration. Very inflexible with media, as your gravel is your filter media.

Moving on to filters with a dedicated pump; hang on back power filters and canister filters are the most common. Hob filters are either flexible or inflexible as far as media choices depending on the manufacturer. They come in a wide variety of sizes, and can be run on anything from the smallest tank to the largest. They are generally better at mechanical filtration than biological, though one manufacturer adds a bio wheel to increase bio capabilities.

Canister filters are generally for tanks that are a little larger. They offer a wide variety of sizes for tanks of 20 gallons and larger. Canisters offer media flexibility, along with a wide variety of convenience options. They are generally better at bio filtration due to the amount of media vs. water flow. With the right media they are suitable mechanical filters.

Sump filters are for large tanks, and provide excellent mechanical and biological filtration. They consist of a smaller tank, usually beneath the main tank. An overflow in the main tank flows into the sump tank, and a pump in the sump feeds filtered water back into the main tank.

Fluidized bed filters are more of a specialized filter designed fore purely biological filtration. They consist of a tube with grains of sand suspended in the flow from a pump. Nitrifying bacteria colonize on the grains of sand, providing a large bacterial colony.

 

[dmarie04]

Wow. Thanks for the detailed responses, everyone! I think I just learned everything (or just about) I need to know about filters

 

[darkleo]

All filters pretty much do the same thing, pushing water through a media to perform biological, chemical or mechanical filtration.