Filtration & Flow

Discussion in 'Filters, Filtration and Pumps' started by johnfw, 15 Nov 2009.

  1. johnfw

    johnfw Newly Registered

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    22 Oct 2009
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    9
    Hi There

    I am setting up a new aquarium for the first time in 20 years which will hold approx 430 litres. I have always in the past used Eheim filters and have been reccomended to purchase the Pro 3 No 2075, which has a turnover of 1250 litres per hour and is reccomended for tanks up to 600 litres.

    I have however seen on the site for 'Filtration & Flow' that a rate for turnover should be at least 10x the tank capacity.

    At this rate I would need 3 of these filters which would be very costly. Is this correct, and if so, what alternative should I be looking for.

    Johnfw
     
  2. chris1004

    chris1004 Member

    Joined:
    27 Dec 2008
    Messages:
    565
    Hi johnfw,

    Welcome to the forum and back to fishkeeping.

    First you'll do yourself a huge favour if you seperate in your mind flow and filtration. The ammount of filtration you will need will depend largely upon the type and number of fish that you'll be keeping or more specifically the ammount of organic waste that you'll be producing which will need removing via filtration. Your filters flow rating can make up all or part of your overall flow rating, a lot of people myself included use koralia pumps (or other powerheads) to add aditional flow. The downside of these is that they are mounted inside the tank and can detract from the overall look if it bothers you.

    Incidently a 430 Litre tank is a massive undertaking when going planted it would be much easier with a smaller tank until you've ironed out the specifics. Such large tanks often have issues because of poor co2 and fertilizer distribution which may well require a turnover nearer 20x tank volume or more to resolve. Although guidelines are good as a starting point ultimatly all tanks must be treated on an individual basis so the 10x rule of thumb is only a rough guideline. If you had 200Lof flow in a 20L tank for instance you'd probably rip the plants out of the substrate conversly 4300LPH on your 430L tank may not be enough without efficient flow distribution. The larger the tank the harder this is to achieve.

    Its also worth bearing in mind that by the time the filter is operational you will probably loose around 50% of the rated flow as manufacturers tend to quote the flow rating as a best case scenario (i.e. empty canister at tank level with very short hoses.). However this has already been accounted for in the 10x flow guideline but at the risk of repeating myself these are only rule of thumb guidelines on larger tanks more flow may be needed.

    I know that I found the figures that we're talking about quite daunting to start with but Koralia pumps do offer a very easy way to supply enough flow cost effectivly. I have 2 koralia's on a timer which come on with the co2 to aid the co2 and fert distribution throughout the tank during the high light cycle. When they are on I have 25x tank volume turnover, when there off its more like 10x but achieved purely through my filters. This is what I have found that I need on a 250l tank with the way I have things layed out and the biomass of plants and fish that I have in there.


    Regards, Chris.
     
  3. jolt100

    jolt100 Member

    Joined:
    13 Jan 2008
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    bury,lancs
    Hi Johnfw, I have a 430l tank and had issues with flow, I hadnt taken in the 10x rule and had about 1800l/hr. As chris says its not just about the filtration its the flow and circulation so I changes from 2 small eheim 2224`s to a new Eheim 2080. The advantage is its got 2 inlets which you can place at either end of the tank. I extended the smallish spray bar to the full length of the back of the tank to help with circulation and placed 2 Koralia 2`s to push the CO2 around. Its helped with my fight with BGA. The other issue is plant mass and placement, I have a large mass of Java fern and anubias growing up the back wall and this seems to break up the flow so I will probably look to starting again and scaping the tank rather than just having a lot of plants trying to grow out of the top.
    The other change I would make is to use an Eheim compact circulation pump outside the tank and position the inlet to collect the bubbles from my diffuser, its easier to hide the inlet/outlet pipes than 2 koralias.

    BTW the 2080 is huge :lol:

    Regards
    John
     
  4. chris1004

    chris1004 Member

    Joined:
    27 Dec 2008
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    Hi again johnfw,


    Just thought of another worthwhile point worth consideration whilst discussing a filtration arrangement. IMO its much more benificial to have two or more filters each able to run the tank in there own right. This is known as a redundant filter system, the advantage of which is that in the event of a filter malfunction the tank is still filtered effectivly thus avoiding ammonia spikes and if the denitrifying bacteria colony was lost in the malfunctioning filter due to lack of oxygen then you won't find yourself in a position of having to recycle a filter with a tank full of fish in residence. Ammonia + light is the cause of algal blooms so it stands to reason therefore that should you need to recycle a filter on a planted tank you are seriously asking for trouble, if you have two or more filters you can 'seed' one from another if you ever have to recycle one.


    Regards, Chris.
     
  5. AdAndrews

    AdAndrews Member

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    22 Feb 2009
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    Location:
    Kidderminster, Worcs
    With that tank size i would either look at getting 2x tetratec ex1200's or a fluval fx5
     
  6. johnfw

    johnfw Newly Registered

    Joined:
    22 Oct 2009
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    9
    Thank you Chris, John and Ad for your valued comments.

    When I was last keeping fish, all I had for filtration was an Eheim No 2013 (which is still in use for my quarantine tank)where water was taken from one end of the tank and returned via a spray bar, which was attatched to the back of the tank, just under the water line. My tank was 60 ins x 12 ins deep x 15 ins high. The bottom of the tank had a 2 ins layer of peat topped by 1 to 2 ins of gravel, and in this system I grew mainly Straight Vallis, (to 72 ins long) Twisted Vallis and Amazon Swords, who's leaves grew out of the water. No additional aids such as Co2 or ferts were used.

    My new tank will be 60 ins x 18 deep x 24 high and I propose to bank up one end of my tank to give a layer effect using slate and fine gravel, with plants behind. If I decide to go down the route of increasing water flow by the use of Koralia's, is there any specific position they should be placed in the tank?. I can get 2 Koralia's No 2 for £29.95 each or a No 3 for £41.95. I also like the method that John Suggests of an Eheim compact circulation Pump. I could get an Eheim Universal 1262 which pumps 3400 lph although this would be more expensive at £94.95. What would be your choice?

    Regards
    John
     
  7. chris1004

    chris1004 Member

    Joined:
    27 Dec 2008
    Messages:
    565
    Hi Johnfw,

    Bit of a milliondollar question that one. So much depends on the tank layout how much access for the pipes you have, your budget, lighting (i.e. high or low tech), co2 diffusion technique, etc etc. the permutations are almost limitless.

    Personally if you decide to use koralia's I would choose two smaller ones over one bigger one every time as it simply gives you more options to address poor flow areas.

    Regards, Chris.
     

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