Aquarium Forum

  · Tropical Fish Home
· Fish News
· Aquarium Forum
· Buy & Sell
· Calculators
· Equipment reviews
· Free Aquarium Ebook
· Feedback
· Link to us
· Photo gallery
· Plant species
· Tropica Plant DB
Tropical fish species
· By Common name
· By Scientific name
Tropical Marine fish
· By Common name
· By Scientific name

        Via paypal

  · African Cichlids
· Algae Control
· Aquarium Decoration
· Aquarium Resources
· Aquatic Plants
· Barb Fish
· Betta Fish
· Breeding Fish
· Catfish
· Central American Cichlids
· Cichlids
· Clownfish
· Corals
· Corydoras Catfish
· Discus Fish
· Dwarf Cichlids
· Fish Diseases
· Frogs and Turtles
· Goby Fish
· Goldfish
· Gourami
· Invertebrates
· Jellyfish
· Killiefish
· Lake Victoria Cichlids
· Livebearers
· Malawi Cichlids
· Marine Aquariums
· Marine Aquarium Fish
· Other Fish
· Pleco
· Predatory Fish
· Photography
· Pond Fish
· Responsible Fish Keeping
· Rainbow Fish
· Shark Fish
· South American Cichlids
· Tanganyika Cichlids
· Tetra Fish
· Tropical Fish Food
Page 1 of 2 12 LastLast
Results 1 to 10 of 35

Hybrid View

  1. #1

    Default Filtration, a repost of my original

    0 Not allowed!
    Filtration is a big issue with aquarium fish. It is an investment, which means although it may be a high initial cost, it will pay you back. It is easy to understand that the extra money invested into a better filtration unit could pay for itself by the fish it saves. There are a vast number of types of filters out there, and among each type is a huge array of filters from all sorts of companies. Filtration itself needs to be understood before the filters themselves are even looked at.

    There are two main types of filtration, mechanical and biological. I do not consider chemical filtration as an essential part of filtration because I have stopped using it and see no adverse affects. It can be used to remove odor or discoloration, but in either of these cases it is treating a symptom and what you need to deal with is the cause. The only other use for chemical filtration is the (hopefully rare) removal of medications. When chemical filtration (carbon) is needed, there are some things that need to be understood. Carbon effectively grabs many types of chemicals in the water, from medications to trace elements. There is a wide range of quality levels in carbon. In general you will get what you pay for, so the highest quality carbon will be more expensive. Carbon does not last forever. The lifespan of carbon is dependent on two main things, quality level and amount of chemicals in the water. On average and along with most recommendations carbon is not effective after about one month. I do not use carbon on a regular basis because it can remove some beneficial substances such as trace elements that the fish need. If proper water changes are carried out the possible consequences of not using carbon should not come in to affect.

    Mechanical filtration is the physical collection of particulate matter in the water. It will trap physical debris and hold it until you clean the filter. While it is in holding it still has a chemical affect on the water. As it breaks down it will end up as nitrates. So although a filter may not be so clogged that it has stopped running, it is decreasing water quality. So the water stays crystal clear, giving the impression that the filter is still working fine even if it is having a horrible affect on the fish. This is why filtration upkeep is a must, even if things look fine. Different media for mechanical filtration will trap different sized particles. Large course media should be the first thing water encounters in the filter. After that point you can have fine mechanical media. There is no point in adding courser media in the filter where the water will have already gone through a finer media because it will not catch much f anything and ill become a media for nitrifying bacteria. Every tank is different so in some tanks the fine mechanical will collect a lot of debris while the course mechanical media seems new and clean, in other tanks the opposite will occur.

    Biological filtration is the most important to the fish. An efficient biological setup is essential to any system. Nitrifying bacteria that consume ammonia and nitrite will live on surfaces where the conditions are ideal. That means the ideal temperature, oxygen levels, and food sources. In an aquarium the temperature is generally uniform, so this will not affect where the nitrifying bacteria will colonize. Oxygen levels and food availability will greatly affect the nitrifying bacteria. Sitting in a corner on the glass or on the gravel will not supply them with the same amount of food as being in biological filtration media where there is a constant high flow of new nutrients and oxygen. This is why the nitrifying bacteria will tend to colonize in the filter on the high surface area biological filtration media. There are many forms of biological filtration media. Surface area is a must. The bacteria need to be exposed to the water so they have to be in thin layers, almost a single layer thick, in order for them all to live. The high flow will bring in the nutrients for them, so as long as there is a decent flow rate that will be taken care of. Oxygen levels are frequently the limiting factor for how efficient the biological filtration is. If the oxygen level in the water is high enough canister filters and other submerged media filters can be quite effective. But these usually require a lot more surface area to compensate for the relative lack of oxygen in order to be as affective as other forms of filtration. Wet-dry and other forms of biological filtration that expose the surface of the media directly to the air are a very efficient way of ensuring high oxygen levels because there can be up to 30,000 times as much oxygen in the air as in the water. By briefly exposing the bacteria to this high oxygen environment their efficiency greatly increases. Cleaning biological media needs to be kept to a minimum to prevent the loss of nitrifying bacteria. This usually means lightly rinsing the media with tank water when debris deposits are visible on the media.

    There is a huge number of filters on the market, all with their benefits and consequences. There are three things that you are looking for: efficient biological filtration, effective mechanical filtration, and the availability to use carbon when it is needed. When these are equal you can look at ease of use and cost.

    Not every tank is the same. So what may be ideal for a highly stocked Lake Malawi mbuna tank may not be ideal for a lightly stocked discus tank. Because of this there is no ‘best’ filter out there. Because of this there is one important issue to keep in mind, the ability to customize a filter. By being able to customize the filter you can meet different or changing needs. The best filter type for this is the canister filter. Most now have multiple trays that allow you to use whatever media you need to. Best of all you do not have to have an exact media. This means that you can use another company’s media (or a cheap generic media) instead of one that has to be made to fit the filter. Most Hong-on-back filters use a slide in cartridge that usually contains the mechanical filtration and the carbon. Many of these actually have the carbon sealed within the mechanical media. In addition most of these cartridges are not interchangeable between brands, so the hang-on-back filters are not nearly as customizable as canisters.

    Sponge Filters: The simplest filters are internal sponge filters. They are powered by air and are a good biological and mechanical media in one. These are best for simple breeding setups where a single pair or group needs to be isolated for ideal breeding. There is no money spent after the purchase of the filter itself, which is cheap. Routine cleaning is a must, usually involving rinsing the debris from the sponge with tank water to conserve the nitrifying bacteria. Simple low stocking tanks are about all these things can handle on their own.

    Internal box air filters: These filters are usually a small plastic box that is air powered and has a cartridge similar to that on a hang-on back power filter. Because the cartridges usually need to be replaced, at least long term, these filters are not as good as the sponge filters at conserving nitrifying bacteria when cleaned. They have a low initial cost but require media replacement.

    Under Gravel Filters: These are an all time classic favorite for many aquarists. These include a perforated plate under the gravel. There are a few variations to this setup. One includes air powered uplift tubes. The second involves a powerhead or other pump to power the uplift tubes. The third uses a powerhead to push water down the tubes, this method is called reverse under gravel filtration. Some even hybridize this with other filter methods and attach the uplift tubes to hang on back or canister filters. This filter uses the gravel itself as a media. The gravel functions as a biological media as well as mechanical media. The high surface area of the gravel provides ample space for nitrifying bacteria. Because of the gravel functioning as a mechanical media, it can trap a lot of debris. This requires that the aquarist keep up with water changes that always include a gravel vacuuming in order to keep the gravel free of debris. Two major problems occur with too much debris in the gravel. The first is that debris can build up and actually choke out the nitrifying bacteria and cut off their oxygen supply. The second problem is that debris buildup can lead to excessive nitrates as the debris slowly breaks down. The plate of the under gravel filter itself can allow debris buildup on the bottom of the tan, out of reach of the aquarist. This leads to excessive nitrate buildup. Many fish are diggers and since water takes the path of least resistance, unless the gravel is the same depth throughout the tank it will not evenly go through the gravel. Once a fish digs down close to the plate, the under gravel filter itself is almost useless. This means that the effective area for nitrifying bacteria is only a fraction of all the gravel.
    Aquarist since 1995
    Biologist and Published Author in Multiple Aquarium Magazines
    Owner: Aquarium Maintenance Company
    Advanced Aquarium Concepts: Articles about many aspects of aquarium care.

  2. #2


    0 Not allowed!
    Internal Power Filters: These are usually an elongated media chamber with a pump at one end. These can provide good mechanical filtration as well as biological depending on their layout. These require that the aquarist actually goes into and disrupts the tank to clean the filter. They can also be hard to tell when they need to be maintained depending on the design. These also use up valuable in-tank space that the fish could use.

    Hang On Back Power Filters: These usually include a box that hangs off the back of the tank with an intake tube going into the tank. They do not use much room at all in the tank. They provide moderate surface agitation depending on design and water level. They are not usually customizable as far as media is concerned. These are generally moderate as far as cost goes. They do require a continued investment in cartridges. Some come with carbon built in so there is no way to not use it, others come with it included, but not built in so you may or may not use it. Many hang on backs have separate biological media. This may involve what is equivalent to a course mechanical media after finer mechanical media. Others include bubble aerated plastic plates, wet-dry functions where the water level itself rises and falls in the filter, and even paddle wheels exposing the media to the air. These filters are easy to maintain, but some designs may take longer. There is generally a low and fixed media capacity.

    Wet-Dry Trickle Filters: These generally involve a large chamber filled with biological media that the water slowly trickles over, exposing the nitrifying bacteria to the water and air. These usually sit under the tank and are gravity fed. The water collects in a sump where it is then pumped back up to the tank. These frequently include separate mechanical and chemical media chambers. The biological media can collect debris leading to excessive nitrates. So these do require occasional breakdown and rinsing to keep the media clear of debris while preserving the nitrifying bacteria. These are generally used on large systems with large bioloads and relatively sensitive fish.

    Canister Filters: Canister filters involve a large canister chamber that sits under the tank. Hoses connect it to the main tank. The canister is gravity fed and a pump returns the water to the tank. These involve a large volume that can be used for an assortment of media. Most use trays to divide the canister into separate sections, each of which can include a different media. These provide a very large media capacity which allows them to handle large tank volumes very efficiently. They require a moderate amount of time to maintain, depending on the amount of debris collected. They are one of the more or most expensive types of filtration. Many include or allow for media that can be easily cleaned and reused, greatly reducing continuous cost. They can sometimes be a headache get started initially and after they have been cleaned and restarted.

    I have found that the best way to determine filtration needed is to simply cut whatever the ‘up to’ rating is in half. This provides enough filtration for a moderately stocked community type tank. High sticking levels or high waste producers like goldfish and cichlids will need even more. I ignore gallons per hour (gph) ratings altogether. Focusing on these can lead to a lot of movement without much cleaning. Remember that the filters are not cleaning x many gallons, they are cleaning up after a certain bioload. Also remember that all the filtration in the world can be undone by insufficient water changes.

    Overall I have found a combination of HOB and canister to be the best filtration. This applies to all of my tanks. It combines the high capacity of the canister with the surface agitation of HOB. I use Fluval canisters on all tanks over about 30 gallons. They have almost no cost to upkeep because I reuse the media and do not include carbon. I use Whisper HOBs because they are effective, cheap, and have cheap cartridges.
    Aquarist since 1995
    Biologist and Published Author in Multiple Aquarium Magazines
    Owner: Aquarium Maintenance Company
    Advanced Aquarium Concepts: Articles about many aspects of aquarium care.

  3. #3

    Join Date
    Dec 2006
    edmonton, alberta, canada

    Awards Showcase

    god im hungry - cocoa_pleco You make me laugh! - Drumachine09 And lots of pizza too! lol - Chrona wish i had some of this to drink right now - cocoa_pleco DAAAAAM, this drink looks good - cocoa_pleco 
    There. Thats better. - Drumachine09 maybe one day we can enjoy one of these - sergo Congrats you recived a RAK gift enjoy! - DemonShark RAK - DemonShark RAK - DemonShark 
    Graves Disease - Lymphedema - Men's Health - Pro Choice - Prostate Cancer - Scleroderma - Thyroid Disease - Trisomy 18 - cocoa_pleco Anti-Tobacco - Colon Cancer - Colorectal Cancer - cocoa_pleco Adoptee - Bone Cancer - Child Exploitation and Abuse - Hope and Support - Peace - Retinoblastoma - Right to Life - Student Sexual Assault - cocoa_pleco Mourning - Anti-Gang - Melanoma - cocoa_pleco World Trade Center Victims and Heroes - Fireworks Safety - cocoa_pleco 
    Cesarean Sections - Headaches - Hospice Care - Multiple Myeloma - cocoa_pleco Arthritis - Child Abuse - Colon Cancer - Colorectal Cancer - Dystonia - Education - Free Speech - Interstitial Cystitis - ME/CFIDS - Reye's Syndrome - Save the Music - Teens Against Smoking - Victim's Rights - Water Quality - cocoa_pleco Childhood Cancer - cocoa_pleco Troop and Military Support - Amber Alert - Bladder Cancer - Endometriosis - Equality - Liver Cancer - Liver Disease - Missing Children - POW/MIA - Spina Bifida - Suicide - cocoa_pleco 


    0 Not allowed!
    good article!

  4. #4


    0 Not allowed!
    This is such a good thread, Fishguy.

    I'd like to see you send the link to this thread to William for his articles.

    Meanwhile, I will stickie it but it would make a great article, too.

  5. Default

    0 Not allowed!
    that is a great article.....thank you for posting it...

  6. #6


    0 Not allowed!
    Hey! Excellent article and thanks for the time you took to do this! These sorts of articles are perfect for beginner like myself who are trying to figure everything out without disaster. Thank you so much!

  7. #7


    0 Not allowed!
    thanks. I had no idea about carbon.

  8. Default

    0 Not allowed!
    There's an error in the description of the canister filters. While this error might be inconsequential to people who "just use" these filters, it might matter to those that want to properly understand their operation.

    Canister filers are NOT gravity fed. It is a popular misconception. Again, it might matter to you or it might not.

    If you want to see a good example of a true gravity feed, take a look at a typical wet-dry filter. The key moment here is that the water volume in a wet-dry filter is not continuous. There's a water pickup line and there's a return line. These two lines operate independently. They are separated by a gap: the filter itself, which is not sealed and is not flooded. The filter itself is essentially an air gap between the incoming and returning water volumes (which is why it is called wet-dry). And the pickup line of a typical wet-dry filter is indeed a good example of a gravity feed: the water is simply siphoned from tank under its own weight. This pickup process required no external power, which is the main feature of the gravity feed. Meanwhile, returning water from wet-dry filter back to the tank requires quite a bit of power (depending on the height difference and the volume per unit of time), so for high-performance wet-dry filters and large height differences you'd need a relatively strong pump. Note also, that if you disconnect a wet-dry filter from external power, it will overflow, since the gravity feed will continue to supply water, while the return pump is stopped.

    Now, let's finally return to the topic of canister filters. The key detail about canister filters is that they are sealed and fully flooded units. In a canister filter, the water volume is continuous (!). The pickup line is filled with water, which leads directly into the fully-flooded inner volume of the canister and then directly to the return line. This water fully fills all available sealed volume (possible air bubbled notwithstanding). In this case the pickup and return lines are essentially two absolutely identical siphons, with absolutely identical gravity feed properties, acting on the same volume of water in opposite directions. These two siphons exactly and precisely counterbalance, cancel each other. Once the canister filter is set up (filled with water), the system cannot "gravity feed" itself (!). The system remains in exact equilibrium, with no self-sustaining feed of any kind possible. The beauty of this approach is that for the purposes of circulation the weight of the water in pickup line fully and exactly counterbalances the weight of the water in return line. Now, all you need to do to make the water circulate is to add a relatively simple water pump. From the filter pump's point of view, the water is weightless, regardless of how far below the aquarium level the filter is installed. This pump does not need to spend any effort to lift the water back to the tank, since the weight of the water is cancelled. All this pump has to be able to do is push the water through the media, i.e. overcome the fluid drag and friction in various hoses, chambers, cartridges, sponges etc. Again, and this is the key point: the pump does not need to spend any effort on lifting the water back into the tank, since in a canister filter the water is effectively weightless (for the purposes of circulation). If you disconnect a canister filter from external power, the water flow will simply stop. (Compare that to the above example with a wet-dry filter. See the difference?)

    Note that because of this important property canister filters (as opposed to wet-dry filters) are fairly insensitive to the height difference between the tank and the filter itself. Regardless of how great that difference is, the siphoning action of the water in pickup line will exactly and precisely cancel the siphoning action of the water in return line. Longer hoses will, of course, create more fluid drag, but that's about it. That means that greater height difference does not require a more powerful pump (Compare it, again, to a wet-dry filter, where a greater height difference immediately requires more power from the pump.)

    Some might ask: why then canister filter manufacturers always warn us about NOT creating too much of a height difference? There's a reason behind this, but it has absolutely noting to do with having to lift water to a greater height (as some people believe and, as you now know, it really not a factor at all). The real reason behind this is pressure. You see, regardless of how low you put your filter, the siphoning action of the water in the pickup line will always counterbalance the siphoning action of the water in return line (so the pump won't have to spend more effort). However, the pressure inside the filter will grow with the height difference. A canister filter is a sealed system and it is critically important to keep it fully sealed. All those sealing gaskets and rings inside the filter are rated to a certain level of pressure. Once you cross that limit, this will will start developing leaks. This is the reason you should stay withing the manufacturers recommended height difference. Again, crossing that limit will not kill your pump (as many people erroneously believe), but will rather kill your seals. (Basically, the reason for this is exactly the same some wristwatches have a depth rating, except that in a filter the water is inside)
    Last edited by AndreyT; 02-25-2012 at 06:52 PM.

  9. Default

    0 Not allowed!
    Quote Originally Posted by AndreyT
    Canister filers are NOT gravity fed. It is a popular misconception. Again, it might matter to you or it might not.
    Of course, there's also such thing as so called "wet-dry canister" filters. When it comes to the principle of operation, such filers are essentially wet-dry filters masqueraded in a canister-like enclosure. These filters are, of course, gravity fed. What I said above applies, again, to ordinary fully flooded ("wet") canister filters.

  10. Default

    0 Not allowed!
    This is the article that I have been looking for. Thanks.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts