• Basics of Filtration and Types of Filters


    In this article i will cover the Different Types of Filtration and their purpose and some most commonly used filters. The need for good filtration cannot be stressed enough, This is like the heart of your aquarium and performs one of the most important tasks of keeping the water clean so that the inhabitants of your tank are healthy. Filtration becomes even more important when you are keeping sensitive species like high grade CRS or Sulawesi Shrimps.

    Types of Filtration:

    Let me first start from the Basics of the types of filtration

    Mechanical Filtration: This type of filtration is used to remove suspended dirt, floating particles and debris from the water column. This type of filtration is achieved by foam, sponge, fiber mesh and similar fine meshed media. Below is an example of a Mechanical Filter Media from an Eheim Canister Filter.

    Biological Filtration: This is the main type of filtration that is required for any aquarium. This mainly consists of media like Ceramic Rings, Bio Balls, Lava Rocks, etc, essentially media which is highly porous which provides a large surface area. Lot of essential bacteria like nitrifying bacteria and microorganisms thrive and multiply in this type of media and the high surface area provided by this type of media directly results in the amount of bacteria that colonize in your filter. These bacteria are found in the tank and form a film over every surface inside the aquarium and are referred to as “Bio Film” but the quantity of this in the tank is not enough. Hence we use Biological Media in the filter to provide a good growing area for these bacteria. These bacteria convert harmful shrimp waste which is essentially ammonia into harmless nitrates which is readily absorbed by the plants as nutrients. Without the biological filtration in place the shrimp waste spoils the water quality and the flora and fauna suffer which also leads to death. This type of media should ideally form 80% of the entire media used in the filter.

    There are commercially available products that have dormant essential bacteria that become active when you add them to your tank. It usually comes in a powder form and can be used underneath the substrate, sprinkled inside your tank and on the biological filter media. This will jump start your Tank cycling process. This can also be used in case you end up wiping out the essential bacteria in your setup for any reason. Some examples of these products are ADA Bacter 100, ADA Bacter Ball, Mosura Bio Plus etc. There is also biological filtration media which come seeded with the essential bacteria like ADA Bio Rio which also reduces your tank cycling time and also has excellent surface area for your bacteria to colonize. To know if you’re nitrifying bacteria and other essential bacteria are doing well, you can use an ammonia/nitrite test kit. These should ideally be zero.Below is a picture of ceramic rings.

    Chemical Filtration: This type of filter is used to remove harmful chemicals from the water in the tank. Activated Carbon is what is used to act as a chemical filter. The life of activated carbon is 7 – 14 days based on the quality. After which it needs to be replaced if required. External Canister Filters come with an Activated Carbon Pad as a part of the filter media. Once a tank is cycled, you really don’t need to have this media in your filter unless you suspect that there are some harmful chemicals in the water. It is good to keep this media handy with you, in case for any reason if some harmful chemicals do get introduced to your tank through the tap water or other sources you can use this media in your filter to nullify the effect of those chemicals on your shrimps. Below is a picture of Activated Carbon

    Some Common Types of Filters:

    External Canister Filters: These are the best type of filters for any aquarium. They have a large media chamber which can be effectively used for housing a large amount of Biological Media. They sit outside the tank and hence make the tank look clutter free. Have a smooth and silent operation. Eheim Filters are one of the best External Canister Filters available in the market. Below is a picture of an Eheim Classic Canister Filter and the ideal way to layer media in the canister filter.

    Hang On Back Filter: Also called as HOB’s, these filters are hung on the edge of the glass, there is a pipe which goes into the aquarium and is used to siphon the water out into the main filtration chamber which sits outside the aquarium and flows back into the aquarium through an outlet. These come in various filter capacity referred to as LPH (Liters per Hour). These are ideal for small tanks. You can put some Biological Filtration Media in the chamber, but the space is very limited.

    Sponge Filter: This type of filter is the most commonly used filters, this filter is placed completely inside an Aquarium and is air driven by an aerator. The main component of these filters is a sponge which acts as a mechanical filter and this works well as a biological filter as well. These again come in various sizes and you should choose one based on your tank capacity.

    Under Gravel Filter: Also commonly known as UG Filter. This consists of a base plate with grooves, The substrate is covered over the base plate. There is a pipe which goes into the base plate and this is the one which is visible above the surface. This filter as the sponge filter is a air driven filter. The essential bacteria colonization happens in the base plate. Some professional breeders use this in conjunction with the External Canister Filter, where the pipe coming from the base plate is connected to the intake of the canister filter. When you are using UG Filter ensure that you use a substrate that does not easily break down, as this will get into the grooves of the base plate and eventually end up clogging it.

    Cleaning Your Filter:

    Yes, there is a right way to do this. Your filter is constantly removing debris and muck from your tank and all this is getting accumulated in the filtration media in your filter. This accumulation reduces the filters flow rate and hence its effectiveness. Ensure that you clean your filter media when you see your filter flow rate has reduced.

    Take some water from the aquarium in a vessel or tub, rinse and squeeze the dirt out from the mechanical filter media in this tub. For the biological filter media like your ceramic rings, bio balls etc, what i usually do is put them in a wide mesh net bag so that they can be easily removed for filter maintenance. Just dip the bag with the filter media a couple of times in the tub to remove large pieces of dirt and debris. Do not give a thorough wash for this media, the concept is simple, if you give it a good wash you will end up wiping away the majority of your bacteria along with it and it takes time for the biological filter to establish again. Another thing that i do is always after a filter is cleaned, i put in some artificial bacteria like ADA Bacter 100 into the filter chamber itself in the cases of Canister and HOB, In cases of other filters i just put this into the tank itself to replenish lost bacteria.


    Never compromise in terms of filter for your shrimp tanks, especially if you are planning on keeping sensitive shrimps, and remember, more filtration is better than less filtration. Ideal rule is to have a Filter with a capacity of 5 times your water volume, so if your tank volume is 100 Ltr, Go with a filter with a capacity of 500 Ltrs/Hr