To Skim or Not to Skim?

Discussion in 'Equipment' started by pixelpixi, Mar 1, 2010.

  1. GreshamH

    GreshamH Guest

    Driving DO into water using aeration is highly ineffective. It's great for off gassing CO2.
     
  2. Gomer

    Gomer Honorary Member

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    it's all relative ;) I had corals that were showing signs of oxigen deprivation until I added the skimmer. I think I also killed a fish without knowing what was going on.
     
  3. Vincerama2

    Vincerama2 Evil Overlord

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    What are the signs of oxygen deprivation (aside from death!)

    In any case, I'll keep my skimmer running, I'm used to the sound that emanates from my stand!

    And aside from the LR in the tank, there is no other "filtration" so I'll stick with it.

    V
     
  4. GreshamH

    GreshamH Guest

    With fish, panting and being lethargic. Corals it's not so easy to tell.
     
  5. Gomer

    Gomer Honorary Member

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    my indicator coral were zoanthids. They NEVER opened (over many months of onset). Within about 1hr of adding the skimmer, they opened. I could open and close the zoanthids by turning the skimmer on and off. I might just be making this up (memory is funny), but I think I also got the same results afterwards with an airstone in the rear chamber of the biocube.
     
  6. GreshamH

    GreshamH Guest

    With out data you just assumed it as low DO :p
     
  7. Gomer

    Gomer Honorary Member

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    Can you offer another candidate given the history, time scales, and an understocked tank as factors? (btw, carbon didn't do anything)
     
  8. tuberider

    tuberider Guest

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    Yeah, you opened a window.
     
  9. Gomer

    Gomer Honorary Member

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    :p nope. no windows there. Could literally turn the skimmer on/off every hour and watch the polyps open/close in sync.
     
  10. Ibn

    Ibn Supporting Member

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    Flow didn't change at all?
     
  11. tuberider

    tuberider Guest

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    I think there are two discussions going on here, some of which are driven by anecdotal information.

    Yes, if DO levels are depressed below ambient levels a skimmer can increase DO. No skimmers do not oxygenate tanks, they can only bring DO levels up to the ambient levels.
     
  12. GreshamH

    GreshamH Guest

    Thanks Jeremy :)
     
  13. Matt_Wandell

    Matt_Wandell Honorary Member

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    I think that was a super broad generalization by him that did not take into account all sorts of variables--how many tank turnovers are going through the skimmer per hour? How does it inject air, and how many lph does it inject? How does water leave the skimmer? Is the air being drawn from inside an enclosed stand?

    I think that certain skimmers do a remarkable job of raising DO even if they don't have any air going in them, just because they create a very thin layer of water when they exit the skimmer that is exposed to air (think ER, ASM, etc, minus the riser tube sponge). Others that are drawing air from inside an enclosed canopy or stand and have a submerged outlet probably don't have nearly the same effect. As is frequently the case, I think EB falls into the trap of taking the effects he sees in a single tank (his own) and makes sweeping generalizations about it like "skimmers don't raise DO that much."
     
  14. GreshamH

    GreshamH Guest

    That comment was dripping in sarcasm for the very reasons you laid out and why I posted the disclaimer at the end :lol:

    This is more to the point though as was Jeremy's follow up about ambient O2 levels.
     
  15. Gomer

    Gomer Honorary Member

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    the whole degassing CO2 is the whole reason FW planted people minimize surface turbulence :D
     
  16. Gomer

    Gomer Honorary Member

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    gresh is NEVER sarcastic!
     
  17. Matt_Wandell

    Matt_Wandell Honorary Member

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    Hey Jeremy, I am trying to sort out the terms here--what do you mean by ambient levels? 100% dissolved oxygen at the temperature of the tank? I think I need a gas law refresher course...
     
  18. Matt_Wandell

    Matt_Wandell Honorary Member

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    Gotcha. Always hard to tell...but I should have known. ;)
     
  19. tuberider

    tuberider Guest

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    I'm referring to the room ambient levels, basically pointing out that if I'm making pizzas and my gas oven is blasting at 700º and I have 6 people n my 600sq ft apt of course my ambient CO2 levels are going to be elevated, no amount of skimming is going to raise my pH or DO unless I open my window. OTOH, if I have a heavy bio-load in a somewhat sealed tank with a high ambient DO then the skimmer is effective in raising DO and pH.

    Just painting with a broad brush to tie the whole thread together, like a nice area rug.
     
  20. Matt_Wandell

    Matt_Wandell Honorary Member

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    Gotcha. :)
     

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