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    Friendly note from GFK. Please review this beginner guide for your fish.

Guide to Cleaning Filters

Discussion in 'All Questions from Newbies' started by *Ci*, Jan 26, 2014.

  1. *Ci*

    *Ci* Goldie Guru

    Joined:
    Mar 15, 2009
    Location:
    BC, Canada
    I would like to clear up some misunderstandings about cleaning filters, why, how and when. I have used all kinds of filters on indoor tanks and ponds, for many years, and have a good understanding of how they work, how to use them successfully, how to maintain them, even how to build them.

    To understand how various filters work, you need to know a bit about the nitrification cycle in addition to understanding what you want your filter to accomplish.

    To simplify:
    Fish produce ammonia as a waste product. If they are alive, they are excreting ammonia, even when not being fed (as in pond fish during a winter fast). They also produce solid feces, and if left in the tank, these feces break down and produce more ammonia, as do decaying plants, uneaten food, undiscovered dead fish and infertile eggs left in the tank.

    In any fish tank or pond, even one without filtration, bacteria that consume ammonia grow naturally. In other words, you do not have to add them, they just exist - the come in from the air, the water, the fish, plants. They cling to all surfaces in the tank and will grow a colony large enough to consume all the ammonia produced as long as there is enough surface area for them to live on.

    If more ammonia is introduced, as in adding fish, fish growing larger and/or feed increased, the colony will expand. If less ammonia is produced, some bacteria will die off. They regulate themselves this way, and in an established tank the changes are virtually imperceptible by us.

    These ammonia eating bacteria create nitrite as a by-product. Once nitrite starts appearing in the tank another type of bacteria start growing (again, appearing out of nowhere and clinging to all surfaces) which consume nitrites and convert them to nitrates. They form a colony as well which co-exist with the other bacteria.

    There are no bacteria that grow naturally in a home aquarium or pond that consume nitrate ... for our purposes, nitrate needs to be controlled by either water changes or perhaps using enough live plants that they take up the excess nitrate. Water changes are important for other reasons, so usually controlling nitrate is not an issue.

    Back to the filters:

    Basically, there are mechanical filters, biological filters, combinations of these (most of those available for home aquaria are combinations) and another category might be fines filters.

    Mechanical filters are used to trap and filter out solid waste and debris. Biological filters contain media that provides large amounts of surface area for bacterial colonies to grow on. Fines filters give a final polish to the water before sending it back to the main body of the tank.

    So let's look at some common filters:

    An HOB (hang on back) filter sucks water through an intake tube usually from somewhere in the bottom half of the tank and sends it through either a foam block, possibly some media in the chamber and/or a cartridge that holds dense fibers and sometimes a layer of charcoal.
    This is primarily a mechanical filter, although with a sponge or other media in the chamber it provides some biological filtration as well. It is meant to suck up solid waste, trap it in the sponge or cartridge and send clean water back to the tank.

    If you don't clean the resulting mulm (dirt, sludge, muck, debris) out of the filter chamber, sponge or cartridge regularly, what happens to it? It decomposes, as it is sitting there, and creates more ammonia. I am going to emphasize this - there is no point in sucking it up and trapping it in the filter if you are not going to then remove it. It is still in the water column and still polluting the tank, just as much as if you had left it on the bottom. In fact, with swiftly moving water constantly pushing against it in the filter, it decomposes even quicker, and crates small particles that get through the sponge or cartridge and back into the tank.

    Cleaning your HOB depends on how it is set up and it's intended use. Due to its size, it clearly does not provide an abundance of biological conversion, but if you have sponges or media in it, it does provide some, and if you have a large tank (lots of surface area on the glass), low stocking levels, a shallow layer of gravel or stones on the bottom (more surface area), and even plastic plants and ornaments, you may not need more from your filter. You may also have additional biological filters to take up the slack, leaving the HOB to be purely mechanical.

    So - if there is a sponge to trap solids - rinse it regularly to remove those solids. The more often the better.
    If your tap water is treated (chlorine or chloramines as opposed to, say, well water) use dechlorinated water or fish tank water from your water change. Running water or squeezing and swishing both work.
    If there is biological media in the chamber (little plastic balls or tubes, ceramic or stone-like bits, things like that) rinse them - they will work better if not covered with mulm.
    If all you have is a "disposable" cartridge, you can do several things. One is rinse it over and over till it falls apart, then replace it, another is to take it apart and put something more durable in the frame, like a thin sponge, or, to get the most out of your HOB, fit in some biological media or a sponge into the chamber before the cartridge and consider the cartridge the final "fines" filter, and replace it when necessary.

    Before I move on to other types of filters, I want to make an important point, one that causes the most confusion, and causes people to advise NOT to rinse your filters often. Beneficial bacteria do not live free swimming in the water and they do not live in mulm. They live on hard surfaces (including the plastic that a sponge is made of) and, in fact, cling tenaciously to these surfaces. They cannot be rinsed off with normal tap pressure, even vigorous scrubbing will not make a serious dent in their numbers.
    As proof, I offer the concept of the moving bed filter, common in high end koi ponds. A barrel is filled with "Kaldness" media, which is a small plastic tubular media, each piece having ridges and wings providing lots of surface area. Pond water passes through the barrel, and the media is kept in a constant rolling boil with large air pumps. The scrubbing action is enormous, and in fact, the claim is that old, dead bacteria are rubbed off this way, making room for fresh, new microorganisms to grow on the media. This is considered one of the best and most efficient biological filters for ponds that are dealing with fish 2-3 feet long and feed measured in pounds per day. There are huge amounts of ammonia to process in these ponds and, believe me, these filters harbour the bacteria perfectly well, despite the banging and constant rinsing they are subject to.

    I have always rinsed my filters once to twice a week, and have never experienced an ammonia or nitrite spike afterwards. As long as you are not killing your bacteria with chlorine, they will survive any amount of rinse offs just fine. If you are still worried, just gently swish all of your filter components in a bucket of tank water - the mulm and debris will fall off, the bacteria will stay.

    Sponge filters and sponge walls:
    Sponges are dual purpose. They are usually set up to suck water through them using powerheads or air bubbles, trapping solids on their outer surfaces, while also providing a great amount of surface area per square inch for bacterial colonies. However, the more clogged a sponge gets with mulm, the less clean surface is available for bacteria, and their numbers can be reduced by essentially being oxygen starved.
    Sponges should be squeezed out frequently - the solids will be removed from the water column and the bacterial colonies will work more efficiently.

    Canister filters:
    These usually have different layers inside that provide mechanical (layers of different density sponges), biological (some kind of specialized media in baskets) and fines (a final piece of fine sponge or filter floss pad). It amazes me that people leave their canisters for months at a time before cleaning. And then describe them as disgusting when they do. Again, if you don't take them apart and rinse the components, it is as if the solid waste were still in the tank!
    Now, canisters are very efficient, and have a lot of room in them for biological activity - a much greater volume of media can be had compared to most all-in-one filters, and, depending on how many fish you have, how much water, etc, they can probably easily handle the extra ammonia produced by decaying fecal matter and debris trapped inside for weeks on end.

    But, and here is my whole point, keeping filters rinsed properly reduces the total ammonia levels in the tank (by removing solids before they decay further) and creates a more efficient environment for beneficial bacteria to grow and consume pollutants in our tanks. This is good insurance for fish health, allows higher stocking levels if you so desire, reduces odors and unsightliness around the tank area and is simply good husbandry.
     
  2. Kat

    Kat Well-Known Member

    Joined:
    Oct 7, 2013
    Location:
    New Brunswick, Canada
    Many thanks *CI*

    I wanted to let you know that I appreciate the time you have taken to write this guide.
    Cheers,
    Kat
     
  3. Cincy Ranchu

    Cincy Ranchu Professional Breeder

    Joined:
    Dec 20, 2008
    Location:
    Cincinnati, Ohio
    Just a few addition notes

    Ammonia to nitrite is controlled by the genus. Nitrosomonas, the nitrite to nitrate is controlled by Nitrobacter. When nitrate is formed by by Nitrobacter there is only three ways for it biologically leave the tank; normal bacteria growth consumes some, if you have an anaerobic patch in your filter or gravel, facultative organisms can use this instead of oxygen, and plants consume nitrates directly.:exact:
     
  4. *Ci*

    *Ci* Goldie Guru

    Joined:
    Mar 15, 2009
    Location:
    BC, Canada
    An additional chapter ...

    Leaving mulm to build up in any type of filter also causes "channeling". Water will take the path of least resistance and bypass the blockages. This creates pockets in the media where fresh, ammonia laden water is not penetrating and so the bacteria that live there die off. These pockets can be anaerobic and large build ups of mulm can also harbour the types of bacteria that are present in internal infections and external ulcers in our fish.

    Undergravel filters

    These filters don't seem to be as popular as they were in the recent past, but are still included in a lot of "starter kits", so I'll address them here. Now that we've covered the how's and why's of keeping filters clean, you can see how an undergravel filter might be problematic.

    This type of filter consists of raised slotted plates that sit on the bottom of the tank with riser tubes in one or more of the corners, and it is covered with a layer of aquarium gravel. Either an airstone is put down the tubes or a powerhead is attached to the top, which pulls water up from underneath the plates. This results in water and debris being pulled down through the gravel, and circulated under and back up. The process can be reversed with water being pushed down through the riser tubes and up through the gravel instead.
    The benefits are that you have fresh, oxygenated water running through a bed of media (the gravel) which provides a lot of surface area for biological filtration and keeps it aerobic, which beneficial bacteria need to survive. The top of the gravel acts as a mechanical filter, trapping solids and debris.

    But the downfall is the amount of work it takes to effectively remove that debris, get it out of the water column and prevent channeling of the water through the gravel bed. The only reasonable means is to syphon the gravel thoroughly and regularly, short of emptying the tank and rinsing everything. It is a chore that often gets put off, or done incompletely, and ultimately build up occurs and compounds. Fine mulm also accumulates under the plates, which can't be reached with a syphon.

    It's too bad, because it is actually a fantastic filter combining more media space than any other type with the look of gravel a lot of people like in a tank, and not a lot of expense. If an easier method of upkeep were found, or if you were willing to do the work necessary to keep it as clean as possible, it could be the best of all possible worlds.

    PS. Cultivating an anaerobic patch in your gravel to possibly control nitrate, as Cincy touches on in the post above, could be an interesting experiment, but in my mind more trouble than worth. By the time you have done a thorough syphon on the rest of the gravel, you will have also done a huge water change, effectively removing your nitrate buildup without any worry about the negatives of anaerobic substrate.
     
  5. rivergardennursery

    rivergardennursery Vendor

    Joined:
    Oct 15, 2013
    Location:
    Abingdon, VA
    Just wanted to say thank You. Very nice job on the write up and should be helpful to a lot of people
     
  6. gillian

    gillian Well-Known Member

    Joined:
    Dec 23, 2012
    Location:
    brooklyn, ny
    I love when i have a question and find the answer so well put on this forum. Thank you!


    Sent from my iPhone using Tapatalk
     
  7. Hinfin

    Hinfin Banned

    Joined:
    Jan 3, 2014
    Location:
    Holland
    This is such a big issue with people using a sump or large filter for GF. Ive seen many giving up because of this factor.

    To add to this, channeling occurs naturally when a thick biofilm is forming. A thin biofilm kind of filtration needs more maintenance usually but prevents alot of these problems IMO.

    There are exeptions offcourse, well established systems that can handle the biological waste usually dont build up mulm as much or as quickly.
     
  8. greenorchid

    greenorchid Well-Known Member

    Joined:
    Jan 16, 2014
    Location:
    New Jersey
    Wow - thanks so much - super helpful!!!!*
     
  9. Just Starting

    Just Starting Member

    Joined:
    Jan 5, 2015
    Location:
    North Carolina
    Wow, thanks, just getting started thinking about goldfish. But this is the best filter summary ever.
     
  10. *Ci*

    *Ci* Goldie Guru

    Joined:
    Mar 15, 2009
    Location:
    BC, Canada
    You're welcome. Good luck in your new hobby!
     
  11. yekaixiong

    yekaixiong New Member

    Joined:
    Sep 2, 2015
    Location:
    Ithaca, NY
    Thank you! This is very informative!
     
  12. RobynO

    RobynO Member

    Joined:
    Aug 4, 2015
    Location:
    Queensland, Australia
    Thanks,
    I thought I had a good grasp of the essentials but this exposition has helped greatly.
    You combine your years of practical experience with the various filter concepts.
    I particularly liked a reference to "biological conversion" which is what is going on, rather than use the word "filter".
    I have noticed in my attempts to select appropriate filter media, notably the "polyester blanket" material from which I would cut pads for the lower trays of my canister unit, that little info is available viz density, porosity, flow resistance, or even basic filter capacity. I have ended up pretty much guessing.
    Maybe more on this?
     
  13. *Ci*

    *Ci* Goldie Guru

    Joined:
    Mar 15, 2009
    Location:
    BC, Canada
    This is a good question but a hard one to answer. Different media can serve different functions and their bio capacity is rarely measured accurately.
    For instance a media like Kaldness K1, sand, or ceramic medias can grow larger and more effective bacterial colonies if they were in a highly oxygenated environment like a moving bed or shower rather than just submerged with water flowing over them.

    Here is a chart of various pond media that's been floating around the internet for years, to give some ideas. Different manufacturers make various claims about the surface area of their products. A good rule of thumb for cannisters is to go with what the manufacturer suggests or similar.

    0071DF65-A882-4866-AD90-1CAFC62C7BFE.JPG


    As far as your polyester blanket material - do you have a picture? It sounds like the type of batting used for fines filtering (removal of tiny particulates) which you would toss out peridically as it becomes clogged, and not counted as bio media.
     
    Last edited: Jul 8, 2017
  14. RobynO

    RobynO Member

    Joined:
    Aug 4, 2015
    Location:
    Queensland, Australia
    My bio-media will be:
    One tray of Seachems Matrix which is pea gravel size pumice AFAIK.
    One or maybe two trays of Marine Pure 1.5 inch bio-balls which are expensive & said to have a very large surface area & not prone to clogging.
    My "first" (bottom) tray is intended to filter out solids, & I have seen umpteen types/grades/descriptions on Amazon/Ebay/LSF and NONE with any reliable info about what size particles can be trapped. Pics of no use here. This was intended as the point of my earlier question.
    Looks like I will just have to experiment?
     
  15. kitkat12

    kitkat12 Member

    Joined:
    Sep 7, 2015
    Location:
    U.S.
    Hey again Ci, I love this! Very needed and helpful info again!

    Hey RobynO- I see you are from down under so I don't know if this will help you or not, but the cheapest I found to get the polyester material is wally-world online, order a whole bolt roll of it! It's the pellon quilters touch 100% polyester batting 96" wide X 9 yard bolt for $24.69! Also for the polyfill batting wally-world has a 10 LBS box for only $19.94! Now I got mine at Jo Anne's fabric & craft store because I made them price match it plus I had a 20% off coupon! And their regular price is like $66.00 for it! so CHA CHING! LOL! If you order from wally-world here in the U.S. it's free shipping if over $50.00 order too. Hope that helps you, have a good one.
     
    Goldie^HawnSolo likes this.
  16. RobynO

    RobynO Member

    Joined:
    Aug 4, 2015
    Location:
    Queensland, Australia
    KitKat,
    Thanks for the heads up on wally-world as a possible source.
    We have very few wally-world stores here, & when I searched they appeared to not stock the stuff you recommended.
    I don't want to buy in quantity until I am satisfied I can properly identify what properties best suit my application.
    The LFS are near useless in this area, possibly because they frequently use large sand filters for particle filtration.
    I am now trialing some polyester synthetic Chamois material (not the imitation leather Chamois); its a sort of poor mans Chamois which I can blow through but less easily than the loose batting. Need to allow a few weeks more before opening to inspect the reaults.
     
  17. goldfishntn

    goldfishntn Well-Known Member

    Joined:
    Aug 25, 2014
    Location:
    Tn/USA
    Wow...I just now found this. This is absolutely the best filter/cycle guide I've ever seen and easy to understand. Thanks a lot.
     
  18. *Ci*

    *Ci* Goldie Guru

    Joined:
    Mar 15, 2009
    Location:
    BC, Canada
    Thanks, KitKat and goldfishntn. Glad that people are benefitting.
     
  19. kitkat12

    kitkat12 Member

    Joined:
    Sep 7, 2015
    Location:
    U.S.
    For those in countries other than U.S.A. who need items shipped outside the U.S., I found this site recommended on a yahoo site for those needing wally-world items shipped to Australia. Hope it helps. I'm in no way making an endorsement as I have no personal experience with them, just as I stated I found it on the web.

    https://bongous.com/
     
  20. chocky

    chocky Well-Known Member

    Joined:
    Jan 24, 2014
    Location:
    WA, Australia
    Don't try to over think it.

    Just a basic sponge or white filter floss will do the job.

    Why complicate things? :)
     

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