MECHANICAL FILTRATION - is it HEART of koi pond system?
  • harry_luhurharry_luhur August 2012
    Posts: 808
    During many years i built pond, join forums, i have seen many hobbyist do not have proper mechanical filtration. Many use "overstocked" japmat/other media which act as mechanical filtration. And have encounter many hobbyist ask for help for NPS, my pond water not clear, my water become green, etc.

    NPS is a situation when nitrification cycle not mature. This will not totally responsible for your unclear water, green water, cloudy water. NPS is a period when nitrification bacteria cultured, and it only to remove ammonia and nitrite to nitrate. And this may cause fish sick, but this due to our false action as hobbyist. Many cannot wait to dump more fishes and start feeding, this may cause ammonia or nitrite boom which can bring fatalities to our kois. I will try to write about NPS in different thread.

    You water condition happen to inadequate mechanical filtration plus feeding, and other debris that polute your pond. If your mechanical filtration is not good, this will pass your biological filter, and return to pond. Some maybe trap in your biomedia, but overtime it get more and more, and it usually happen 3 days to 1 week after you put your fish.

    The common respond for above situation is WAIT, your pond is in NPS stage. But in my experience, if you put proper bacteria starter, you ammonia and nitrite should reach the safe point within 1 week at the most. And why the water not clear, some respond wait again another 2-3month, until you filter mature. And then YES, some reach the clear water stage after 2-3 months but many still fighting it, and begin asking WHY THIS HAPPEN???

    The reason is, some have more biological media such as japmat, which is get clogged over time, the media void is getting smaller and smaller. More debris get trap and less pass to pump chamber and back to pond. Some with fewer media will never reach that stage because too few of media to trap the debris. More layers mean more faster your water clear up. Let's us check using clear glass, how much particles get though your mechanical chamber, bio chamber and water return to pond.

    And how many times we hear that hobbyist clean their bio chamber, and water get cloudy, and all blame to biological media? The same reason actually happen like above, since we clean our media, all the void clear again, and debris pass to pond again, the cycle is coming back again. Bacteria attach very strong to media and not that easy to die, unless you clean it with chlorinated water or let it dry. Cleaning with pond water and put it back to filter will never kill you bacteria, as long as it still wet, it will survive.

    This is not the only cause for cloudy water, but usually what always happen. Wrong water circulation and water flow also sometime responsible for cloudy water. The debris and pollutant is not transfer to filter as soon as possible but keep circulating in pond, and even 1% can cause trouble overtime.

    Mechanical is the heart to closed circulation system, the cloudy water is accumulated of small particles and DOC. Try to use commercial product to clear water, this usually a coagulant, the bind small particles into bigger debris, and when you clean your filter, you will surprised to see how much it is.

    Final word, CLEAN WATER IS NOT ALWAYS GOOD, BUT CLOUDY WATER IS DEFINITELY BAD.
    Regards,

    Harry Luhur
  • IndraWIndraW August 2012
    Posts: 33
    nice article bro....totally agree with you.
  • 4r4sis4r4sis August 2012
    Posts: 66
    thanks for the info bro harry. btw what is the best mechanical filter recommended? does a normal brush filter enough or there is still room for improvement.maybe like pre-filter by bro david..
  • BthineshkumarBthineshkumar August 2012
    Posts: 1,763
    Thanks Bro Harry for the info...
    I also only have brush as pre-filter, need to improve the filter by adding the filter mesh...
  • gerrygerry August 2012
    Posts: 777
    Bro Harry,

    I don't have all these Jap Mats and brushes... just the sand filter for my 3.6 tonned pond. Is that sufficient? My water is always clear but I dunno about what is "inside" the water i.e. NH3, NO2 and NO3.

    I also have biological media (4 bags of corals). Do you think all these are sufficient or should I add more?

    Thanks in advance.
  • jamiltjamilt August 2012
    Posts: 287
    sis gerry, why dont u carry out water test? either home test kit or use proffesional services?
  • harry_luhurharry_luhur August 2012
    Posts: 808
    Dear Bro and Sis,

    To tell the truth, i haven't found the perfect MF so far. Some have good effectiveness but difficult on maintenance, also the other way around. Have something that meet both. effectiveness and easy maintenance but very expensive so it cannot suit for common hobbyist.

    PREFILTER
    The basic of MF is prefilter and the MF filter itself. Prefilter basicly use to filter big solid waste, algae, leaves, etc. Commonly use media/system such as :
    1. Vortex/Settlement Chamber : Both this system is used for settling the heavy particles.
    A. Vortex can be used if you have big enough diameter and slow flow. If you can see water swirl in slow water movement, then your vortex is working, though not 100% effective, because vortex need output from bottom, and this swirl movement help to drag the solid waste to bottom. Pond vortex use outlet from the top part, and most is small size, all small particles cannot settle and big particles also not settle if you have high water flow.
    B. Settlement Chamber can work effectively on wide and long flow. The slower the flow, the more effective solid waste to settle.
    2. Brushes : This can be effective against big waste, algae and leaves, but hard to totally clean it. Also very difficult if have algae and leaves attach to it. You have to take out and clean it individually. Just spray in filter chamber event using pressurized pump, will only clean the upper part. Need to pack more dense for more effective.
    3. Japmat : 2-3layers of japanese mat can help as prefilter. It have smaller void compare to brushes, but can get clog faster if many leaves present. Cleaning is moderately easy if you have pressurized pump.
    4. Strainer/sieve : This mostly effective against big solid, leaves, algae, etc. Easy to clean but more easily get clogged if not clean regularly. Strainer can use as prefilter or MH depend on mesh size you use. Using strainer/sieve as MF will need more frequent cleaning. Bro David's sieve and Neli's Izeki are fine examples of this category.

    MECHANICAL FILTER
    MF in here mean to remove small particles or DOC that cloud the water. Many have available to market, from old timer to new technology.
    1. Filter cloth : This come in many form, from reusable until dacron cloth that can only clean a few times. This cloth already use for a very long time, and still use until now. You cannot spray directly to the cloth, give some angle for it to collect the solid particles (similar to commercial sieve). If you spray it, the waste will split into smaller particles that will cloud your water because of spray. When solid reach through the other side of the cloth, you have change it. I find this the most cheap and effective way against the small particles, for dacron can be clean 1-2times, or simple change it if get dirty. It cost more cheaper than your water bill to clean your biological chamber and easier to change than to clean.
    2. Sieve : Many commercial product available for sieve, including our own system on multilayers of Japmat. Commercial Sieve rely on stainless steel mesh to filter the solid waste. Many hobbyist don't realize that their japmat is actually a sieve. Commercial sieve is easy to maintenance, but mostly come on small size and you need few for bigger pond or else you need to clean it regularly. While with Japmat, as my previous article, i have mention about it very clearly.
    3. Sand Filter : SF is the best MF against small particles. The problem is without proper prefilter, it will get clogged easily. And the main problem is when backwashing, you need big powerful pump for backwashing, without it, trapped waste cannot be clean totally and you need to clean/change sand over a few months. SF also need regular backwashing, 1-3 days depending on accumulation of solid waste. Without proper BW procedure, pump will get backpressure and it can shortened you pump life. Some people actually worries about anaerob condition in SF, it will never happen due to heavy water flow, unless you turn off you SF for few days.
    4. Fludized Bead Filter : FB is designed due to ineffectiveness of SF backwashing, others is just marketing gimmick. It can act as biological filter, SF is also the same. FB due using light material is easily cleaned using air movement. With automatic backwashing (SF also have auto BW, but the effectivity of BW is the main problem), FB so far this is the latest and best technology on MF. The effectiveness of this system also depend on the media it use, smaller media mean more effectives on filtration.
    5. RDF : RDF technology already introduce to market long time ago in waste water treatment. Recently introduce to koi hobbyist and gain popularity. Based on what i experienced, you also need more unit to make sure you have adequate flow. And spraying bar also responsible to make very fine particles, over the time i experience a little bit foggy on the water. Beside that, it also need regular change of screen because of slime buildup inside the screen. This also good MF but it comes with expensive price.

    At the end, most MF can be use on our system, depending in what you want and what you willing to spend. Most new technologies come with expensive sometime unreasonable price but this that ease the maintenance process and give you more time to enjoy the hobby.

    I had many experiences when the pond owner want to maintenance the pond itself or ask his worker to do it, but over time the also got lazy and some over confident due to their clean water. Any filtration without proper clean mean you have a ticking bomb inside your system waiting to explode.
    Regards,

    Harry Luhur
  • harry_luhurharry_luhur August 2012
    Posts: 808
    Sis Gerry,

    I have seen and test on a pond that totally use 2 sand filter only. No biological media available, and water quality is good and water is good. I check ammonia, nitrite and nitrate also found nothing unusual, all is in safe zone.

    [img]http://i596.photobucket.com/albums/tt46/36aquatic/FF/Pond%20with%20FF/MrAhong-Medan01.jpg[/img]

    But i am not suggesting you do the same, this need routine BW and measure water parameter. Sand can act as biological filter media, but it also need to change regularly. Unless you have minimum 2unit that you can maintain on different time, please do add bio media.
    Regards,

    Harry Luhur
    Post edited by harry_luhur at 2012-08-08 03:42:56 pm
  • ShukriShukri August 2012
    Posts: 4,881
    Nice pond Bro Harry. Thanks for sharing the picture. And I can see why two sand filters is practical as you need to BW regularly and not having to lose all of the good bacteria during the BW. So alternating BWashing the filters will be very good as to keep healthy bacteria from being washed away in totality.......
    In Koianswers Forum, no one individual is above the rest. This is the Forum for the Koi Community.
  • harry_luhurharry_luhur August 2012
    Posts: 808
    This is my friend pond Bro Shukri,
    Learning from here, i usually install 2 smaller SF and using 1 pump as source. Normal filter running, pump split into to SF, and when do BW individually, i get bigger power pump that can clean better.
    The pump is bigger capacity to use for each SF, but ok for BW purpose. If using the same pump to 1 SF, the SF cannot handle the pump big flow.
    Regards,

    Harry Luhur
  • Ivanlo24Ivanlo24 August 2012
    Posts: 133
    Dear Sifus,

    May I know how many cycles of water going thru the filter per hour is the best?
  • ShukriShukri August 2012
    Posts: 4,881
    IMHO opinion, minimum is once per hour, one and half is good and twice per hour is probably a little too fast.
    But most importantly, is the contact time (or enough contact time) for the aerobic bacteria to neutralize the Ammonia, Nitirites and Nitrates adequate? The design of the system should answer this..........

    Lets see what the others have to say about this..........
    In Koianswers Forum, no one individual is above the rest. This is the Forum for the Koi Community.
    Post edited by Shukri at 2012-08-08 05:43:59 pm
  • ShukriShukri August 2012
    Posts: 4,881
    BTW,
    For those that have issues with mechanical filtration, why don't you consider Waterco Multicyclone. I am using two of these and have worked wonders for my pond. I am only flushing these 2 to 3 days once only........
    In Koianswers Forum, no one individual is above the rest. This is the Forum for the Koi Community.
  • HDCuHDCu August 2012
    Posts: 1,117
    Bro Harry,

    I have a question about sand filters acting as both mechanical and biological filtration.

    What kind of bacteria will proliferate more in a sand filter only setup, heterotropic or nitrifying bacteria? I asked this because in ponds where oxygen saturation is not high, is there a danger that heterotropic bacteria will colonize and push out the nitrifying bacteria in a sand filter especially so that there is no oxygen introduce when the sand filter is running. As I know heterotropic bacteria multiply at a much faster rate as compared to nitrifying bacteria. Assuming you fail to clean as schedule the sand filter, will the heterotropic bacteria multiply fast enough to reduce the nitrifying bacteria?
  • harry_luhurharry_luhur August 2012
    Posts: 808
    Depend on pond design, size, volume, total stock and feeding regime.
    I have try 3hour to 1/2hour per cycle. For small shallow pond, 2 hours percycle still can work, but for big pond, at least 1hour percycle. Small pond have limited area and easier for fish waste to directed to BD, big pond have more area where the waste is slower to move.

    For shallow pond, water jet in top may help water movement on bottom of pond, for deep pond, the botttom water will not be affected by surface movement. Water jet in water surface or air ring may help water movement toward surface skimmer in 3-4m pond length. But for 10 meter, it lost momentum/power, so need bigger power.
    Regards,

    Harry Luhur
  • harry_luhurharry_luhur August 2012
    Posts: 808
    Bro HDCu,

    I once also believe in what i read, but i also like to try things out. When i first introduce the pond owner, i always also skeptical. I test 2days in row, and 3-4months after that. Ammonia and nitrite is in save level, nitrate is around 10ppm. As i remember, pH around 7.3, tds 140 and DO level is around 5,7-5,9, temp around 28-29. All fish grow well, healthy, body bulky, and almost never have any fish sick. BD is directed to 1x1m sump chamber where pump deliver to SF and back to pond.

    Owner want to increase DO, so i put protein skimmer, and DO increase to 6,8-7,0. But no foam produce, this is the only pond i put PS that do not work instantly, water very thin, due to periodical BW. Most pond will start producing foam, and may reach this pond stage within 2-3months. And here what i notice that thin water make fish grow faster with good skin quality. Thick water always produce more problems, mostly is fishes easily get sick.

    By water testing, i believe that nitrifying bacteria is working here. Beside we alsoknow that bacteria is also attach to pond wall and piping. As long as you have big water flow and your water contain oxygen, you SF will not become anaerob. For detrification which we create anaerob condition, water flow is slow, maybe few liter only perhour.
    Regards,

    Harry Luhur
    Post edited by harry_luhur at 2012-08-08 06:24:11 pm
  • HDCuHDCu August 2012
    Posts: 1,117
    Bro Harry,

    Did you perform the test after a backwash or when the sand filters pressure has increased and really needs a definite backwash?

    Also after four months, did you notice any "smelly sand" yet?

    I do also think four months is too early to tell. Maybe after a year and a half without changing the sand media.
    Post edited by HDCu at 2012-08-08 07:18:37 pm
  • harry_luhurharry_luhur August 2012
    Posts: 808
    Bro HDCu,
    I forget to mention this is not new pond. When i install the protein skimmer around early, the pond alredy run for few years. The owner is old timer hobbyist, the oldest koi i remember asking is around 7 yo.

    He do 2x daily flush, morning and afternoon, and water thin is due adequate water change. I have a second thought that ammonia maybe due water change, though it seemnot possible because i do the testing around 1 o'clock. But i do test the water source and i don't have nitrate present. So my conclusion is there are nitrification bacteria present in the pond. I do testing using sera and tetra test kit.
    Regards,

    Harry Luhur
  • HDCuHDCu August 2012
    Posts: 1,117
    Bro Harry,

    Thanks for the clarification. I have read in some forums that the sand inside the sandfilter can get covered with slime and biofilm and causing sand to stick together and compact that even backwashing may not be enough to "clean" thoroughly as such there is a need to open up the SF and manually break apart the sand. How true is this?
  • smokersmoker August 2012
    Posts: 715
    Bro Harry,
    Our brother that own the pond with 2 SF is actually very much considering changing the SF as MF, but still have difficulties to find spaces. I went there last week and we discuss about the options too.

    He has already have to change the sand every 1-2 months, he said can't be longer than that, problem comes quickly. He does 10% daily water change minimal, PP in pond when needed and do lot water change. His SF also use very heavy electric consumed submersible pumps.

    He doesn't recommend SF as MF for friends who intend to build pond.

    Personally, i really don't think it's good for long term MF. And if we use as MF, we have to change the sand very soon regularly as the sand is hard to clean. But to use SF as water polisher is ok.

    One other friend who also use SF and changes the sand every one or two months, now are using ozonizer plugged in the sf to sterilize the sand when operating. He also want to change it but it would be quite a problem too due to limited space.

    As a newbie, I really agree MF is the heart of pond filtration, it's the most tricky and hardest one. If one day i am fortunate to build a new pond, i'd love to have some RDF and BF too :-))
    Post edited by smoker at 2012-08-08 08:51:20 pm
  • harry_luhurharry_luhur August 2012
    Posts: 808
    Bro Wahyu,

    Is this happen recently? The backwashing procedure will become problem is pump is not powerful enough or worn out. If i remember correctly, he told me that he change sand every 3 months. If it become clogged within 1 or 2months, then this possibly because worn out pump, so the backwashing not clean, and this main problem with SF.

    I lately try using 1,5power for 2 SF and result quite good for backwashing. Example for SF need 1HP pump, so i use 1,5HP for 2SF, when running i split, so each using 0,75HP power but for BW, i use whole 1,5HP power. This combine with adequate prefilter is enough to use. Usually for swimming pool sandfilter, sand is fill around 70% and usually fine grain. I use around 40% with more coarse and round sand, this can help when backwwashing. Silica sand normally have sharp edge, if not enough power to backwash,it can get compacted and more difficult to backwash.

    What i found annoying is not changing the sand but doing the backwashing. Because this mean you have to standby or at have ppl doing while you travel.
    Regards,

    Harry Luhur
  • gerrygerry August 2012
    Posts: 777
    Thanks bro Harry for all your explanation. :)

    Bro HDCu, it is true tat u have to open the SF to clean the sand. I do it almost every week. I just unclog the sand with my hand then put the valve to BW. Will use around 20-30% of pond water to completely clean the sand then I close it back again. I personally have not had to change the sand and It's been years already.

    Pond water is always clear n fishes have always been healthy... Except recently when I added two new babies... Hehehe... Due to my impatience at quarantining... But that's another story la... :)
  • harry_luhurharry_luhur August 2012
    Posts: 808
    Sis Gerry,

    If you want more easier, go to LFS and ask for aquascaping handpump. I will to take a photo tom. It actually a2" plastic pipe with 1/2" hose. When you put in sand, all debris and particle will be suck out, but the sand is not because it is more heavier. It's very easy to do.
    Regards,

    Harry Luhur
  • smokersmoker August 2012
    Posts: 715
    Yes, recently Bro Harry.
    He uses heavy electric consumed submersible espa pumps for his SF too.
  • Ivanlo24Ivanlo24 August 2012
    Posts: 133
    Thanks bro Harry and Bro Shukri. The concern for the no. Of cycles is with the break down of the waste into smaller particles and therefore difficult to settle in the settlement chamber. Right now I am doing 2 cycles per hour. Should I consider a sieve as my water still has smaller particles floating around?
  • HDCuHDCu August 2012
    Posts: 1,117
    Turnover must be relative to the size and flow length of the filter area. If flow rate is too fast then small particles are not given a chance to settle whether in the mechanical or biological area. If you put more resistance like a seive or compact the jap mat filterd you can reduce the small particles even further but you may possibly have more drawdown of water in the filters.

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