Why must skimmer be in 1st chamber?

Discussion in 'Biological/Natural Filtration and Deep Sand Beds' started by RiaanP, 18 Aug 2009.

  1. RiaanP

    RiaanP Moderator

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    Something that always bothered me.

    Why must the skimmer be in the first chamber? Especially an In sump skimmer?
    Is there any proven rules for this type of setup?

    Or does this order originates out of the old sump designs where you had skimmer chamber, bio-balls and ceramic rings chamber then your return chamber. So that you can remove hopefully enough solids before being trapped in the bio-balls and ceramic rings.

    How does this "traditional" design fits in with more recent use of scrubbers / ATS and DSB's?
     
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  3. dogstar

    dogstar

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    Good question.

    I would like to ask (and it might in part answer your question) in the last chamber, the chamber you are going to see water level changes (as a result of evaporation), if you have an in sump skimmer, will the water level changes affect the skimmer?
     
  4. Manic

    Manic Moderator

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    Also if it is in the last chamber you get a lot of micro bubbles going in to your display and it also might kill a lot of pods where as in the first chamber it wont do this...
     
  5. Neil H

    Neil H Moderator MASA Contributor

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    Hi Riaan,

    My take on this is that it is about the philosophy with which you approach the filtration of your system.

    In My system, i have the skimmer first, this is IMO to get rid of the major particles of waste ... no matter what other systems of filtration i have, i want to get as much rubbish out as quickly as possible, i find the skimmer does this very well. Now that the big particles are gone, i try to get rid of the organic particles.... this i do through my biological filtration compartment which has a DSB, a ATS and macro algae ... lastly i try to get rid of chemical compounds through carbon etc in my return chamber.

    However

    If you decide to go with an ATS as you primary method of filtration, then you would run the ATS first then the DSB etc (something like Mudshark has)

    For me it goes about a logical process of removing the largest particles first, the the organic compounds then the chemical compounds..... there has been much said about skimmers vs ATS, but little said about running both in tandem, i have just done what seems logical to me

    Without a doubt, the compartment you have your skimmer in MUST have a stable water level (for an in sump skimmer) a change in water level of anly a few mm, will effect what i refer to as the bubble popping level of the skimmer, thereby skimming wetter or drier as the case may be ...... This is one of the reasons an auto top up device is so important !
     
  6. Neil H

    Neil H Moderator MASA Contributor

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    An excellent point..... if you are using the DSB as a refuge as well, you definately dont want a skimmer to skim out all your pods before they have a chance to get to the DT
     
  7. RiaanP

    RiaanP Thread Starter Moderator

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    I do not understand this part. There is a pump that pushes water in with air bubbles. And the height of the bubble popping level is determined by the outlet pipe. At least on my Reeftek TS2. If I move the outlet higher, the popping level goes higher and I get wetter skimming, lowering the outlet the popping level goes down and I get drier skimming. This surely must be related to the skimmer design.

    Also, on an in sump skimmer, not all water goes through it. Be it in the 1st or last chamber. So if first it cannot catch all big particles and on last it cannot catch all pods.

    Thinking a bit wider.
    If the DSB is first, any food going down the overflow can directly go to the critters on the DSB.
     
  8. Neil H

    Neil H Moderator MASA Contributor

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    That was my understanding as well, however if you think about it in greater detail, the pump operates on "head" i.e. the height the water must be pumped (in this case to the outlet point on the TS2) now the head is also related to the height of the water column above the pump (i.e. the height of the water in the sump)..... so if your water level drops, your pump essentially has to work harder to achieve the same head (because the water pressure on the pump has been reduced), but our pumps work at a set work rate, so this drop in sump water level results in an apparent increase in head resulting in a decrease in skimmer performance... i hope i am making sense here. The difference in my TS2's performance before i had the ATU vs once it was installed was simply chalk and cheese, and i changed nothing else.

    The rate at which water travels through my sump is very slow, in general the flow is not good enough to keep things in suspension, so the muck that lands up in the skimmer compartment generally is skimmed out or settles in this compartment (which being bare bottom is easy to get rid of during monthly maintenence.

    Yes if you put a DSB first you would feed the pods etc, but IMO the aim of the filtration is to clean the water, not feed pods, pods and other life that gets into the DT is a bonus for me, i do not rely on it as a food source. the amount of muck that gets past my skimmer is more than enough to feed a very healthy pod/feather worm/ bristle worm etc etc population in my sump....

    I would perhaps question the need for a skimmer if the philosophy to be used was running a DSB first in order to feed the pod life??

    It basically boils down to the philosophy you decide is best for your setup
     
  9. Pugsly

    Pugsly

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    I have two sumps connected to each other via two 50mm piping that flows from one to the other.

    My first sump, where my inlet from DT is, flows in, (I have a UV filter here to that pumps from this chamber and back into this chamber) then through a baffle over the DSB through a baffle and through the two 50mm pipes, into the 2nd sump where my skimmer is.

    I did this about two weeks ago and I have noticed no difference in the skimmer. It skims just as it did before. I chose this setup to allow for more "food" to get to the DSB so as not to starve the critters that I have there.

    I put my UV filter first in the 1st sump at the inlet (that only turns on when the DT lights are off, but the pump is always on) cause it does heat the water slightly, but this water cools down by the time it exits the last sump due to the time it has had to flow through all the sumps / DSB / overflows etc and piping.

    But my setup works fantastic like this. Just my 2c
     
  10. SchyffS

    SchyffS Reef Aquarist

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    Hi, here is my understanding:
    1. Skimmer intake, although in both cases i.e in sump or external skimmer, a maximum flow rate is prescribed to ensure effective skimming. The bubble pop level is adjustable however, a constant flow rate or water head is required to ensure consistent skimming at a consistent bubble pop level. No consistent water head/pressure/flow causes either pop level to overflow or underflow. Requiring adhoc tweaking....this is undesirable.
    2. Skimmer outlet, contains very fine bubbles that is undesirable if plumbed to the return chamber as it will end up in the Display Tank(DT). Also it is highly oxygenated and is beneficial to the critters in the Deep Sand Bed(DSB) if plumbed here first and allowed to settle feeding the critters with clean water as well. Its all proportional.
    3. The DSB does not require a huge amount of food, however the corals and fish do and thus increasing the amount of organic waste to the DSB does not make teh DSB more effective. The DSB produces beneficial nutrients that can be taken up by corals and fish as a food source, providing the corals and fish with this food source is the priority, thus maximising the amount to be avaialble in the DT is first choice. Placing the skimmer in the retuen chamber reduces the amount of beneficial food source returning too the DT. Only technically unacceptable. The DSB is thus placed after skimming to ensure that it feeds the DT with the natural food source.

    Depending on your bio load, you may use both skimmer and ATS, if there is enough organic matter to feed both then why not install both. Just ensure that the feed to each is sufficient to maximie each seperate filtration effectiveness.
    Agreed, that the main point is to ensure that Nitrate and Phosphate remain as low as possible.
     
  11. Nemos Janitor

    Nemos Janitor

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    Always remember MCB mechanical, chemical, biological.

    1) A skimmer is a mechanical filter tool to remove proteins, organics and other waist substances produced in our aquariums. As are filter mats, sponges, strainers etc.
    2) Rowa Phos, Phosban, elimi Phos, carbon, chemi pure etc etc and their reactors are there to chemically remove those impurities produced within the aquarium.
    3) Aerobic, anaerobic, algae scrubbers, mangrove, DSB, Plenums, Aiptasia beds etc are biological filters.

    Why that order? Well I would suggest that first one would want to remove the organics, proteins and other solids before they enter and foul the chemical or biological filter systems. Eliminating these solids and waist before they enter the biological system reduces the nitrogen cycle. What I am saying is that if you remove waist before it gets to the biological stage the lower the nitrite and nitrate production. IMO

    The chemical stage is much debated as to its necessity. It is often seen as an expensive lazy aquarist’s way of fixing something that can be done biologically. I agree. But it is also very convenient. That said for chemical filtration to be effective the water needs to be as free of organics and protein as possible else the media gets contaminated very quickly.
    Now we all know (hopefully) what the difference is between an aerobic and anaerobic filter. In order for these to function efficiently the lest waist (Detritus) that enters this system the better.

    Hmmm... Now let’s do some homework and consider the pros and cons of the suggestion.
     
  12. RiaanP

    RiaanP Thread Starter Moderator

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    Ok, Nemos Janitor highlighted one REAL reason to convince me why skimmer first, that is if you have chemical filtration and it is to keep it clean for so long as possible.

    But because all the water from DT do not go through the skimmer first some rubbish do go past directly into the chemical filter. So blocking the chemical part actually. So really the outlet of skimmer should directly enter the chemical and the other none treated part bypass the chemical to meet up again after the chemical chamber.

    Also if skimmer in return chamber and its pump is next to the return pump. Then beneficial stuff from DSB got 50% change (OK depending on pump size) to either go directly back to DT or to the skimmer. If Skimmer first you remove food that DSB critters can eat (Or part of it).

    Now the reason for this thread.
    Sump chamber takes space and the return chamber, and if these 2 can be combined into one single chamber that take a lot less spaces, then you have more space available for a bigger DSB.
     
  13. inflames

    inflames

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    Now the reason for this thread.
    Sump chamber takes space and the return chamber, and if these 2 can be combined into one single chamber that take a lot less spaces, then you have more space available for a bigger DSB.[/quote]


    Hi Riaan,

    I would like to know how combining two chambers into one will save space? All you are doing is removing a piece of glass 6mm thick...surely this cant make your DSB that much bigger?!?!?!:whistling:
    The space taken by the return pump and the skimmer would still remain the same, so there would be no point! The only way to maximise your DSB footprint and have the sump set up optimally would be through planning the sump layout BEFORE starting ones tank! This would allow for the sump design to be specific for the DT and the relevant pump and skimmer to be measured (the space they need) and planned for!
     
  14. RiaanP

    RiaanP Thread Starter Moderator

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    How to make the DSB bigger.

    "Traditional method"
    Skimmer 300mm
    DSB - whatever space you have, let us take 500mm
    Return 200mm
    Total sump length = 1m

    My suggestion, same 1m space

    last chamber skimmer and return together 300mm
    DSB the rest so 700mm
    And small entry block, overflow method of 100*100mm for drain pipe from DT.


    That will be 36% bigger DSB.
     
  15. Furbz

    Furbz

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    i agree and will be implimenting this method.
    as for my skimmer, it will go in the last chamber with the inlet getting its water from the very first chamber. and the outlet pumping back to the first chamber. (will be using an external skimmer that will be placed in the sump)
    all to try and get the biggest DSB possible!
     
  16. inflames

    inflames

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    I see where you are going with this... it would be great way to increase the DSB foot print by having it this way...also thought about having and external return pump fed from a 20mm hole drilled into the side of the sump in the last chamber? This would also allow for making the last chamber even smaller (say 100mm). So you could still keep your skimmer in the 1st chamber?!?!;)
     
  17. RiaanP

    RiaanP Thread Starter Moderator

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    As they say, a picture tells a 1000 words

    [​IMG]

    This is a 1m by .5 sump.
     
  18. dallasg

    dallasg Moderator MASA Contributor

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    ok my 2c
    Riaan as u mentioned that an in-sump skimmer cant "process" all the water so why have it first, well that why in-sump skimmers are cheaper as they in my opinion are not as efficient as external's connected directly to your overflow.

    but as Nemo J said MCB, as you want the "purist" water over your bacteria, i agree your dsb etc will be bigger but at the expensive of in-organic dirt fouling things up.
    I have skimmer, chemical then mechanical again then my dsb etc then again this hobby is all about what works for you
     
  19. inflames

    inflames

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    And if you make the return pump external you will have even a bigger DSB! As you would only need space for the skimmer!
     
  20. Furbz

    Furbz

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    hang on. how does a external skimmer plumb into the overflow? ar they fed by gravity and then the pump is used to suck air? i'm confused as to how to plumb an external skimmer..
     
  21. dallasg

    dallasg Moderator MASA Contributor

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    exactly, there are many ways to skin a reefing cat

    yip thats the way, i know JacquesB has it setup like that...
     
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