Flow through Systems

Discussion in 'Tank Talk' started by Scouse, Feb 8, 2006.

  1. Scouse

    Scouse Haliphron Atlanticus Registered

    Jul 24, 2003
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    I have a million and one questions on this subject and am eager to find out how you run one exactly, so hope to add questions as responses come :smile:

    I think I remember someone possibly Carol mentioning that their piep came from a couple of miles off shore might of been couple of hundred meters on my memory!! :lol:

    So how far off shore would you go and why exactly :?:

    Is it to stay away from the coast as poo gathers their :?:

    Also how do you maintain the inlet on the pipe and would this just be a big grill kinda thing with other filters as you come in :?:

    Loads more but sure thats enough for now :smoke:

  2. TidePool Geek

    TidePool Geek O. vulgaris Registered

    Jul 18, 2005
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    Hi Scouse,

    If your aquarium is intended to model the local environment a flow
    through system can have some real advantages:

    1. Water temperature - Handled (assuming that there isn't too long a
    run from the shore to your tank)
    2. Water chemistry - Handled
    3. Plankton for any suspension feeders - Handled

    There are, however, some pretty serious potential problems as well.

    1. Recruitment - The intake piping is an absolutely heavenly
    environment for all manner of suspension feeders. The system that I'm
    involved with needs to be cleaned or replaced several times per year
    because it gets 90% clogged by worms, barnacles, mussels, etc. This is
    in spite of the fact that we actually have two intakes that are
    alternated monthly in order to kill off the clogging animals.

    2. Gunk - There's a lot of microscopic stuff that will come into your
    system and then settle out. Left unattended, your rockwork would
    almost constantly look 'dusty'. That problem is pretty easy to deal
    with but it does require attention at least weekly.

    3. Catastrophes - Depending on where your intake is and what is going
    on in the area, things can go very wrong almost instantly. Several
    years ago the local port authority authorized some dredging adjacent
    to our intake. The resulting turbidity killed virtually every animal
    in the facility. We've also had two or three instances of storms
    coming in from unusual directions that also caused excess turbidity
    and 10 to 30% mortality.

    4. Pumping capacity - The distance from intake to tank will make an
    absolutely huge difference in the size of the pump you need. I don't
    have exact figures but based on my experience pumping various
    materials I think that doubling the length of the run will require
    quadrupling the size of the pump in order to maintain the same flow
    rate. BTW: This and the recruitment problem both argue in favor of the
    largest diameter pipe you can handle.

    There is no hard and fast rule about where to draw your water.
    Obviously, you want clean water but that doesn't necessarily mean that
    you have to go far offshore. Your best bet is to look at where your
    intake might be located and then compare what lives there to what
    lives in areas that you consider to be pristine. The water depth at
    the intake site can be pretty important. If you can draw your water
    from a spot where the depth is at least double the maximum expected
    wave height (3 or 4 times would be better) you'll reduce the chances
    of a catastrophic turbidity event.

    Screening your intake is useful for keeping drift algae out of the
    system but won't do a thing about recruitment (remember that these
    little guys come in as almost microscopic larvae). You would want the
    screen area to be as large as possible to prevent stuff from being
    sucked onto and clogging it. I think you would get good results with a
    200L plastic drum with numerous large diameter holes cut into it and
    then screened over.

    In the final analysis, I suspect that there are vanishingly few
    situations where a flow through home aquarium is practical.

    Practically yours,


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