Fishkeeping Tips 6: Filtration and Water Quality

    Filtration has the single goal of maintaining adequate water quality in your aquarium. You cannot over filter the
    water, and the turnover of an aquarium's water for minimal filtration should be at least 5 times per hour. Basic
    texts teach that there are three types of filtration, and many filters available for sale make a point of providing
    mechanical and biological filtration, with the use of chemical filtration coming from the choice of filter
    medium. (The use of ammonia absorbing zeolite, or activated charcoal are considered chemical filtration.)
    Some filters can be very interesting, as well as amazing to watch, such as the fluid bed and wet/dry filters.
    Filtration can be as complex as you prefer, with the added expense you would expect. What is not expected
    is that when a tank is set up with cleanliness and simplicity in mind, an appropriately sized filter of most any
    type will keep the water just as clean as the expensive filters also available. Expensive filtration hardware
    gives you a tank that is filtered many times per hour with little disruption to the look of the tank, or provides
    high quality biological filtration from a medium that rarely, if ever needs to be changed. But the water won't
    necessarily be any cleaner than it is with an $8 box filter. No properly maintained, adequately sized filter
    works to maintain long term exposure of the fish to unhealthy water.

    These fish prefer water movement and moderate to heavy aeration, so an expensive filter, great for a show
    tank of angelfish or discus, isn't required for any of these fish. In fact, cheaper aeration-driven filters would
    be preferred by these fish evolved to live in streams with some water movement. Your choices range from a
    $20 air pump and box filter combination that need to have the floss changed every 4-6 weeks, to a nearly
    silent $50+ canister filter (Which still needs to be cleaned with about the same frequency). Keep in mind that
    any type of wet/dry or canister-type filters that siphons water out of the tank can leak or break, with the
    potential to spill, and because that has happened more than once over a number of years I no longer use
    those type of filters. They are generally very dependable, but just once can be an experience that is not
    easily forgotten.
    The type of filtration used in our120 tank fishroom takes the overall set-up into consideration as well as
    stocking levels, with a need for low cost, simplicity, and operation of the automatic water changing system
    that provides regular water changes. Filtration needs to be of high quality to reach maximum growth in high
    stocking levels, heavy, multiple feedings and an expectation that the fish will breed as soon as they are capable.
    With most types of technology this would suggest a costly solution, but effective aquarium filtration is actually
    fairly simple. Mechanical filtration is accomplished by running the water through some type of medium
    that catches particles, but won't easily clog. Biological filtration is provided where the mechanically filtered 
    water can pass through material of colonized bacteria. These will digest excess organic material (In wet/dry 
    filters, for example, bio-balls serve this function). Chemical filtration comes from the option of using 
    ammonia absorbtion or activated charcoal filter with the filter floss.

    The simplest, most inexpensive, durable and effective air driven filters are the 4" box filters 
    based on a filter that used to be far more common in the hobby. Costlier filters are generally easier to
    service (you may not need to put your hand into the aquarium), and they provide little disturbance or disruption
    to the tank. Most involve a motor and an impeller that must be cleaned, with some type of large box that holds the
    filter medium outside of the aquarium. These box filters costs $9, whereas small, motorized filter will start at
    about $25. I prefer box filters that do not require an airstone that can clog, while requiring more air pressure from
    the air pump. The box filters here provide excellent mechanical filtration (especially when 2-4 inch 1/4" rigid tubing
    extensions are added), with a medium of marbles to weight them down and provide some biological filtration,
    covered with polyester floss, available at any hobby store. (Often sold as as aquarium filter floss in the pet stores.)
    The floss should be replaced monthly. The box filters have no parts to wear out, and there are some in use that
    are over 30 years old, working as well as the day they were bought.

    The tanks are bare bottom, keeping down the need for the cleaning and filtration required to counter a gravel bed
    harbors deteriorating organics. The result are relatively easy to maintain, heavily planted bare bottom tanks that
    operate simply, with consistent, predictable maintenance. When there are problems, the water becomes cloudy
    and can be spotted easily to be addressed with a 30-40% water change. With the tanks maintained this way,
    every tank can be easily monitored.

                       Practices that contribute toward high water quality

    - Feed to get the maximum amount of food into the fish. Pellets are better than flake, all will deteriorate,
    mold up and add ammonia to the water if not eaten. Frequent small feedings, rather than one big feeding,
    ensure the fish eat the food put into the tank, with minimal excess.

    - Keep stocking levels low. For fish under 3 inches, "an inch of fish per gallon" works out pretty well. Some fish
    handle density better than others, based on the efficiency of their digestion. The least efficient are the Goldfish
    and larger predators that produce the greatest amounts of waste. They are least efficient at digesting what they 
    eat, requiring more space per fish. Active fish that require higher oxygen levels and prefer to eat smaller
    amounts of food more frequently, such as the barbs, rasboras and danios are the most efficient, and can
    be kept in larger numbers when provided adequate aeration. Some fish, such as the anabantids (Gouramis
    and bettas), possess the ability to breathe air directly, and can tolerate poorer water quality. The livebearers
    offered here are best fed smaller amounts more frequently, but do well being fed once per day. Not particularly
    inefficient eaters, mulm will still collect if not kept at bay, and higher oxygenation with some water movement is

    - Keep tanks bare bottom, using floating plants or plants in easy to remove and clean around pots. The
    standard 1' of gravel works well when it is kept reasonably clean and looks natural, but all gravel will collect
    organic waste that isn't seen that will quickly contribute to an unhealthy water quality. The bacterial foundation
    provided by a layer of gravel is beneficial, but most aquariums with the maximum number of fish generally
    generally produces more waste than bacteria alone can assimilate. The solution is to use a very thin layer of
    gravel (1-2 stones deep) can be used to provide colonized nitrifying bacteria, especially when a tank is prone
    to become cloudy, without the depth that will collect deteriorating organic waste. Some fish must have a healthy
    presence of nitrifying bacteria to do well. They literally will not thrive when the water is  "too clean". One species
    this has been the case with has been the Limia nigrofasciata.

    - Use Live plants. Live plants contribute to clean water by breaking down organic waste, and some aquarists
    keep tanks using live plants as the only form of filtration (combined with siphoning waste off the bottom,
    keeping low stocking levels and water changes). The fish also do better in tanks with live plants for a number
    of other reasons, keeping the water oxygenated and providing shelter for both adults and new fry. The water
    here is fairly soft, and plants grow well, and the Rapid Grow Fertilizer is used to ensure that the plants are
    growing at their best.

    - Keep a bright enough light over the tank 10-14 hrs. per day. Not only will the light enable plant growth, but
    light also helps to ensure consistent, healthy bacterial growth.

    - Siphon up mulm that collects. This can't be overstated, a lump or collection of accumulated uneaten food
    behind an ornament or rock in a tank can be quickly and simply siphoned up to remove a source for ammonia
    that by itself affects the overall water quality of the tank. Mulm is not inert, nor is it harmless, and its benefit
    by providing a source of food for infusoria that fry feed on is, in my opinion, negligible.

    - Do water changes. One way or another, the fish and all of the waste produced stay confined together in 
    a closed system. These fish have evolved from environments of moving, constantly replenishing streams and  
    open bodies of water. Water changes are today understood to be absolutely essential for normal growth and  
    breeding. Water changes of at least 20-30% per month (and weekly is better), is simply a must for an  
    adequately maintained aquarium.

    - Temperature/Water Quality- This is tricky as most species do best within a specific temperature range,
    so fish requiring a similar temperature range should be considered when choosing tank mates. Cichlids,
    for example, must be kept in a warmer tank than fish that prefer cooler water, such as some loaches, minnows,
    barbs and rasboras. Cooler water holds more oxygen, and cooler tanks possess a lower rate of bacterial activity.
    Warmer water encourages bacterial growth, which can encourage deterioration of organic waste. Unfortunately,
    oxygen levels in a warmer tank are already lower, so a dirty tank (or the introduction of a dead fish, for
    example) may overwhelm a warmer tank, harming the healthy residents (triggering fungal infections, skin,
    respiratory and digestive diseases, etc.) more quickly than in a cooler aquarium. Fish will grow more slowly
    in cooler water (and generally become larger), and will generally have longer lifespans. Fish in warmer water
    will grow more quickly, reach sexual maturity sooner, but may live overall shorter lives. Some species, however,
    especially highly developed domestic fish such as delta tailed guppies, do best in warmer water to maintain
    their immune systems to support their exaggerated finnage, when their wildforms do well in cooler water, but those
    exceptions are few. The livebearers sold here, with the exception of the Goodeids, do best at 72-76 degrees.
    Goodeids prefer cooler water, doing best at 68-75 degrees. the Odessa barbs, though considered a cooler water
    fish, do best in slightly warmer water, showing best color and willingness to breed at 76-80 degrees.

    The result is that keeping your water temperatures in the lower range of the fish's tolerances will lead to
    better overall water quality, and be possibly better for the fish that will live longer and ultimately grow larger.
    For those keeping a standard tank of fish commonly kept in the hobby, this would mean keeping a tank at around
    72-76 degrees (non-cichlids), rather than 76-80 degrees often recommended by beginning aquarist literature. For
    fish accustomed to warmer temps, slowly bring the temperature down over a week or two, for a sudden drop of
    temperature could trigger a bout of ich or other malady that can occur when fish become chilled. The goal is a
    tank that stays at a clean, consistent operation less prone to bacterial swings that can cause die offs and
    occasional disasters, such as when they are accidentally overfed, or when a fish dies.

    With water changes being done on a regular basis of at least 20% per week, filtration comes down to
    the amount of water movement and aeration the fish prefer, the right size filter for your tank and the amount
    of money you want to spend. For the fish offered here that are generally under 5 inches, the box filters do an
    excellent job inexpensively. With other commonly available filtration options, other aspects of the filtration
    operation may need to be considered. You will not want a powerful hang-on- the-back filter if there are going
    to be fry present that could be sucked up, or a sponge filter for a tank of large cichlids, as it won't keep up
    with the waste they produce.)

    Inexpensive, durable, and simple make for consistent, reliable fishkeeping. Provided the water movement
    within the tank stays reasonable you cannot over- filter an aquarium. Use filters that cycle through all of the
    water in a tank at least 5-15 times per hour. Pay close attention to maintaining consistent, effective filtration
    in every tank. As to durability, the box filters mentioned above, because of their simplicity, work as well
    now as they did when new, 30 years ago.

    If you have a number of tanks, consider a blower or a linear piston pump to produce larger quantities of air.
    A single unit is cheaper and more reliable than a large number of smaller air pumps. With any filter, always
    inspect for "blow by" where water flows past or over the filtration material as it becomes clogged or may
    have been installed or settled incorrectly. This type of compromise is common on most filters and can
    entirely undo the unit's filtering capability.

    Avoid undergravel filters because they specifically pull and store the waste within the gravel. They
    revolutionized the hobby when invented in the 1950's, but there are better alternatives today that do
    not keep the dirt in the tank, or require a regular disruption of the fish on the scale that an undergravel
    filter system does. The large amount of gravel required for an undergravel filter to work well (3/4 to1 inch)
    collects, in my opinion, too much organic waste, and plant roots also do not do well growing over an
    undergravel plate. Then, if a spot is cleared by a fish or an object is moved, an opening in the gravel
    quickly compromises or ends the entire plate's filtering capability. Lastly, fish can and do get trapped
    under the plate, and there is little you can do short of tearing the entire tank apart to get to it. Sponge
    filters are good for tanks with fish that do not produce a lot of waste, or tanks with small fry. Keep in 
    mind that sponge filters do need to be cleaned occasionally by rinsing thoroughly in clean, established
    aquarium water (so as not to kill off the colonized bacteria). Keep an eye on sponge filters so that they
    do not become compromised as the sponge material deteriorates, and remember to siphon out detritus
    from the tank that the sponge filter cannot collect. For these maintenance and cleanliness issues, sponge
    filters are not used here.

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