No matter whether you have a freshwater or saltwater aquarium, a fish tank filter is a must. All animals produce excrement either through breathing or from food waste. A fish aquarium is a very limited environment and this waste, unchecked would eventually contaminate the water and kill off your fish. Fish tank filters will clean off this waste and ensure that you have a clean aquarium all the time. Filters, because of catching dirt, also get dirty themselves and therefore have to be changed every so often.
There are 3 steps in a filtration process, and each step requires a different filter.
a. Mechanical Filtration: This sucks up floating particles and debris in the tank. A siphon filter usually located at the back of an aquarium is the one that does this best.
b. Biological Filtration: This is the most important filtration to have in an aquarium because it encourages the growth of good bacteria. The good bacteria converts ammonia waste to nitrites and then into nitrates. This nitrogen cycle is critical, especially for tropical fish!
c. Chemical Filtration: This removes dissolved waste from the water. Carbon or zeolite is placed in a filter and they will both do the job, although carbon has a much shorter lifespan.
There are different types of fish tank filters, and these will vary depending on the type of fish tank in use.
1. Corner Filters: These will typically sit in the corner or be stuck to the glass. They usually are able to do all 3 parts of the filtration cycle, but need frequent maintenance. When changing filters, the only thing you have to do with these filters is change the carbon portion.
2. Under-gravel Filters: These are usually good for beginners in aquarium keeping. They use a combination of both the filter and the gravel to keep the aquarium clean. They have a big disadvantage though: because they use the gravel for part of the filtration process, you often have to vacuum the gravel clean – no easy task. They also tend to capture poisonous air bubbles in the gravel which can be released and poison your fish.
3. Sponge filters: These are good especially for biological filtration. When water flows through a tube and into the sponge, good bacteria grow on it. However, there is no mechanical filtration or chemical filtration. You will need to change water very frequently with this kind of filtration because of this. It’s good for bare-bottomed tanks, especially those that hold young fish; the frequent water change makes them grow faster.
4. Power Filter: This is the most popular type of fish tank filters. It is easy to clean and it does the full filtration process. It combines mechanical, chemical and biological filtration. They are clumsy in design though; the entry for the dirty water is just above the exit for the clean water. If you want a power filter, get one with 2 filter media slots. All you have to do when cleaning the filter is switch from one side of the filter to the other, and this means that you don’t throw out the accumulation of good bacteria.
5. Canister Filter: These are expensive, but it’s because they’re highly effective. It comes in the form of trays, with each tray doing a different filtration process. The water is pushed from the bottom up in some of them, but in others, it’s the other way around. You need to know how yours works so you can place it correctly.
6. Protein Skimmer: These are specifically for salt water tanks – they are useless in fresh water tanks. They remove dissolved organic matter from the water. The waste will cling to them. Its one of the best things that you can get for your aquarium though a bit pricier than a regular filter.
7. Powerhead: Salt water tanks usually need more water movement than fresh water tanks to ensure that all water gets mixed and that food particles move around and are either eaten by the fish or get into the filter. These are good for water movement; although they have to be used with an undergravel filter system. Water is cleaned through the filter and the forced upward and out, causing movement.
Fish tank filters are critical for aquarium! When you are setting up your aquarium, you need to know which one would be the best for your kind of set up.