Pros and Cons of CLS (Closed Loop Systems)

Discussion in 'Pumps and Waterflow' started by RiaanP, 30 Jul 2010.

  1. RiaanP

    RiaanP Moderator

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    My Primary water flow is a closed loop system. I already got my own personal reasons why I prever CLS over any internal pumps. So giving my opinions upfront will affect your comments.

    But what do you guys prefer, and WHY. What advantages do CLS have, what is your opinions. Also what do you see as problems. Do not quote other websites. I want to hear your own reasoning.
     
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  3. ziyaadb

    ziyaadb

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    Cons:
    BIG pump needed
    We do not have ocean motions 4 way/ 2 way splitters avail in sa to split flow left and right
    Very direct narrow laminar stream.
    Cannot be directed

    why i use stream pumps:
    less electricity used
    can be positioned anywhere in the tank
    ready available
    wide flow
     
  4. RiaanP

    RiaanP Thread Starter Moderator

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    Nobody else brave enough to voice their opinion? :)

    CLS do pop up sometimes in other threads, but I do not find one the specifically discuss the Pro's and Con's. So lets do it...
     
  5. shane

    shane

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    Hi,
    Just for what is is worth, there are similar device like the oceans motions here in SA. I have seen them available from a supplier in the greater joburg area.I am not to sure if I may mention the supplier's name or web site here as they are not sponsors. They are quite pricey as well which may be a down side to using them.
    Cheers
     
  6. neo

    neo

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    I have no experience with CLS but from the few tanks I'v seen:

    Pros:
    Neat/Clean looking tank.

    Cons:
    Big pump needed.
    Flexibility

    Not sure of:
    Positioning the outlets.

    I would like to make use of CLS to get rid of the internal pumps and wires hanging over the tanks back pane but I'm concerned that one would go CLS and then end up needing pumps in the DT as well due to wrong design.
     
  7. Jaco Schoeman

    Jaco Schoeman MASA Contributor

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    I have had some use with CLS before.

    Pro's:

    Looks better than those ugly freakin powerheads.
    If done right, a CLS can be fully LS and Nennie safe.
    Gives nice chaotic flow
    No internal heat from pumps if you use external pumps, vs. powerheads that generate heat.

    Con's:
    -If you do it right, with large pumps, high pressure fittings and pipe, then a CLS can be very expensive. The one I built cost me the same as two Tunze pumps (no controller though) would have cost me for the same sized tank...
    -I used two 5500l/ph pumps, each consuming 90W electricity. I could have thus used 12x 15W powerheads before reaching that wattage.
    -You are a bit limeted with direction etc. Yes, you can place bends that swivel, but to move a nozzle up or down the tank, means replumbing.
    -The external pumps makes more noise than powerheads, unless you submerge them or you tank is built into a wall. But open plan it is just too noisy.


    All in all, a closed loop is good, but has some drawbacks if you just want to have a marine tank in your livingroom, neat and tidy, with low noise.

    If however, you have money, power consumption is not an issue, and you have the means to silence the huge pumps you need, then CLS is a good thing.

    Personally, next time I'd go with Tunze pumps rather, and just not keep any LS that might get hurt in the powerheads.
     
  8. Neil H

    Neil H Moderator MASA Contributor

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    i have thought loooong and hard about what flow system to use in my drop off tank, and chose the cls for a number of reasons.

    if done correctly and with a little thought, they are
    neigh on invisible
    can and do creata random /chaotic flow
    are Anenome, sea hare etc friendly
    Are NOT as power hungry as some believe IF you spend lots of cash up front on a low power usage pump.
    Again if built with a little thought are adjustable

    Cons
    no where near as easy as powerheads to adjust
    low power pumps are expensive (but then so are the high end powerheads)

    Powerhead Pro's
    cheap
    low power
    easily produce random flow (as opposed to it being more difficult to achieve randome flow with a CLS)
    Can produce those revolting marine tank waves so many people seem to like.

    Powerhead cons
    UGLY
    not nennie safe
    UGLY
     
  9. RiaanP

    RiaanP Thread Starter Moderator

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    And CLS, I do not have to remove the pumps every second week to clean them. What a schlep job. And all those wires into the tank, introducing magnetic current.

    CLS.
    Marginally adjustable. Last lenght of pipe inside the tank do not need to be glued, so you can replace it with longer or shorter piece, and use elbows.
    Pumps, yes bigger, mine 13600L/h uses 115W.
    Plumbing, especially those ballvalves can set you back easily another R1000 or more. More pipes to glue, more places that can leak. (Been there, done that...)

    But in summary
    On my old 1.2m tank, just the effort and time taken every second weekend to remove and clean the powerheads, then I rather pay the extra on power consumption.

    And if done correctly, a CLS can be totally Nennie safe.
     
  10. Suhayl

    Suhayl

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    CLS if designed properly will rock a tank. Power hungry I dont think so, lots of energy efficient pumps available, example Bubble Blaster. Why clean the pumps, my friends running his for 3 years without servicing and still running at full power. CLS can be hidden nicely under rockwork so you dont any extra ugly pumps at the top. There are some very nice CLS systems on Reef Central check it out. Well it can be done neatly that if you up for it.
     
  11. martin

    martin Reef Adict

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    Hi Riaan
    IMO:
    Pros of CLS:
    Very little heat exchange
    Cheap (and pricey see cons)
    Neat
    Lower maintanance
    No conductivity
    You can adjust direction with elbows etc but affects flow amount
    Safer if protected inlets
    Reef safe
    Cons:
    A more concentrated flow
    Noisy if not a good pump
    If something goes wrong with plumbing can be a bit more than just messy
    If done properly could be pricey with plumbing and taps etc

    I will be going CLS on my new setup but with pool pumps - so my vote is for CLS.
     
  12. herkie

    herkie R.I.P.

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    The best tank I ever had was a closed loop setup. A pump intake in the middle of the tank below the rocks and a pump outlet on both sides close to the tank ends facing down and inwards. This tank had very few algae and other irritating issues and if any arised it seems to have gotten sorted out quickly. The only disadvantage I had was caused by myself when I did not fit gate valves between the pump and tank making it very hard to work on the cls system. I am busy with a slightly bigger tank and it will have a cls.
     
  13. HenkHugo

    HenkHugo

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    Righteo - i have a 12 000l/h Lifetech pump which i want to use in a CLS. How do you make it nennie safe?
     
  14. seank

    seank

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    :welcometomasa1:
     
  15. HenkHugo

    HenkHugo

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    ummmmm..... been here a few years :thumbup:
     
  16. RiaanP

    RiaanP Thread Starter Moderator

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    here is my solution, 50mm pipe, 200 holes 6mm each. Will be behind the rockwork.
    [​IMG]
     
  17. seank

    seank

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    @%#%. Dunno what happened. Posted the welcome on the new Sponsors Thread and it came out here.
     
    Last edited: 26 Aug 2010
  18. HenkHugo

    HenkHugo

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    ag atleast i know i am loved Sean :D

    Thanks Riaan - i was thinking along those lines!
     
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