Filtration pros/cons......

By: Jbeing75

The debate is on. Which is the best? Which is the worst? Why do we use different types of filters for different types of fish? What filter is best for my specific tank setup? In this post we will discuss the three main filtration types. What are the pros and cons to each? What is best for a specific tank setup? The areas covered will be mostly for freshwater tanks as saltwater tanks use a more complex system of filtration often including sumps and overflows that a normal freshwater tank would not include.

So first what are the most common types of filtration? The most uncommon and sometimes considered obsolete form of tank filtration is the under gravel filter system. The second is probably the most common type of filtration system used in general aquariums today, the hang on back or power filter. The final type of commonly used filter would be the canister filter, which mostly are used with larger tanks but some prefer to use them on all tanks.

The under gravel filtration system usually consists of a system of one or two plates that are rigged and are set under the gravel when first setting up the tank. The corners of the plate/plates have predrilled holes in them big enough to fit a piece of clear or colored piping on it that will run vertically up the tank and connect into power heads. The power heads suck water through them at their rated speed and create a siphon in the gravel pulling all suspended material down into the gravel. The pros of an under gravel system are that suspended particles are usually pulled down into the gravel keeping the overall tank appearance very clean and free of debris. That is about the only pro with the system. The disadvantages highly out number the advantages. The disadvantage to these systems are they are virtually impossible to run with sand or any fine particle substrate as it will end up being sucked through the plate and into the power heads. Another disadvantage is that the gravel commonly does not hold enough bacteria to sustain a full cycle and keep the decomposing waste and food particles from creating higher levels of ammonia and nitrites. The gravel needs to be vacuumed on a very rigorous schedule to completely remove the debris left behind since it is always pulled into the gravel. The biggest disadvantage to under gravel filtration is there is virtually no media choice available.

The hang on the back or power filter is the most common filter used for recreational aquarists as it is widely accessible, cheap and come in many different variations. The most common quality hobs include Aquaclear, Tetra Whisper, and Marineland Emperor and Penguin series filters. There are other options available like Top Fin, Aqua Tech, and various other brands but these often include less media options than the higher quality hobs. HOB filter pull water from an intake tube that is user adjustable with attachments. The water is pulled up the intake by a propeller and sent into the filtration hold in the filters. Different hobs have different filter media options. The Aquaclear series has more media options than other hob filers. It’s mechanical filtration stage is a sponge, then a carbon bag or most prefer just loading it with biomax (ceramic rings). If you have ammonia problems you can also load the aquaclears with ammonia remover bags as media. Whisper and Marineland filters usually have less media capacity and include pre-made carbon filters. However, biobags can be purchased and stuffed with whatever filter media the user prefers. The cheap price, numerous filter media options, and low energy use make the hobs the most commonly used filtration system. The only real disadvantage to hobs is in a planted tank scenario where little water flow on the surface is required to keep needed CO2 in the water.

The final filter option would be canister filters. Canister filters are often used on larger tanks and by aquarists who have a general preference for them. They are external filters and generally set beside or under the tank and are used commonly in aquariums that are meant to be viewed from both sides. The sleek intake and return tubes allow for the front and back to be viewed where a hob would block the view from either side. Canisters pull water through an intake and into the canister. Once in the canister the water is filtered in a 3 stage process as the hob. First stage is mechanical filtration which is usually a sponge or some type of fiber material. The second stage is the chemical stage which generally would include carbon or for most ceramic rings. The third stage is the alternate chemical stage and again would be ceramic rings, biomax or some even use a high polishing fiber to keep the water crystal clear. The advantages to a canister filter are external filtration so no visual blocks on the tank, they are generally larger than hobs so they can carry way more filter media allowing for more bacteria development on the media and decreasing the risk of recycles, and last they allow attachments of spraybars which allow controlled movement of water streams by the user. The only real disadvantage to canisters is the initial cost of the unit.

As for overall performance the canister may be a higher stability filter but if you have adequate filtration on your tank with hobs you should not be able to tell the difference. The best bang for their buck will be the hob as the cost for a high performance hob that filters around 100 gallons would be $60. For a canister that will filter 100 gallons general price range will be $150-$200. At the end of the day it is user preference and what has worked the best for them though. Hopefully this will help out a little.

Other Aquarium Articles

Aquarium Cycling - A guide on how to cycle your aquarium.
Aquarium Lighting - Learn the basics of aquarium lighting
Acclimating Fish - A guide on how to acclimate fish.
Breeding Fish - Overview of How To Breed Tropical Fish
Beginner fish - Great Beginner Fish for the Beginner Aquarist
Bad beginner fish - Horrible Beginner Fish for the Beginner Aquarist
The beginners tank - A guide to your fist aquarium
Cleaning your filter - Basic filter management
Carbon and aquariums - Information on the effects of using carbon in your aquarium.
Cycling - A guide to aquarium cycling and how it works.
Don’t trust the staff in the fish store! - A text about why you shouldn't alway trust your fish store.
Dry and Rainy Seasons in the Tank - A detailed account of how to simulate seasons in aquariums
Electrical Safety and Aquariums - How to prevent electrical accidents.
Fry Growth rate - Thoughts on how to optimize growth in fry.
Fish keeping for beginners - An introduction for beginners.
Aquarium Filtration- Llists and describes the different methods of aquarium filtration, and then discusses their benefits and drawbacks.
Finding the Triggers - Information about how to find breeding triggers in different fihs species.
Fry Savers - Information about fry savers and how to construct fry savers.
How to Buy Healthy Fish - A gew tips on choosing healthy fish.
Making a Pebble Cave - A guide on how to make your own pebble cave for your fish.
Modifying Water Chemistry - A technical article about modifying hardness, alkalinity and pH.
Optimizing Growth of Fishes - The factors affecting fish growth - some may be manipulated, others not.
Setting up a tropical freshwater aquarium - Detailed guide on how to setup a freshwater aquarium..
Reverse Osmosis and aquariums - RO is a way to get very pure water in which fish such as dicus and neon tetras can breed and raise their fry.
Safe Rock and Wood Aquascaping - How to make sure that the materials you use in your aquascaping are aquarium safe.
Selecting Community Tank Fish - A guide that will help you choose the right fish for you based on tank size and experience level.
Setting Up A New Aquarium - Help beginners setup their first aquarium
Slime coat - Protecting your fishes vital slime coat
Snails in Aquariums - The biology of snails. Their advantages and disadvantages in an aquarium. How to keep them in check.
Amazon Biotope Aquarium - How to set-up, stock and maintain an aquarium that replicates the Amazon watershed.
Wall mounted aquariums - Information about Wall mounted aquariums
Water chemistry in the aquarium - Hardness, alkalinity and pH are discussed technically, from a chemistry point of view.
Water Chillers - Introduction to water chillers.