air exchange

Discussion in 'New Members' started by Tim S, 10 Aug 2009.

  1. Tim S

    Tim S

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    Hi guys

    One of the important issues to keeping marines way back was the need get oxygen into the water. To do this one had to break the water up as small as possible to give it greater surface area for most efficient air exchage. What was done is to drop the overflow water over plastic "hair curler" like objects and then into the sump. I do not see anyone talking about oxygenation of the water. Is it assumed that the skimmer does this adequately?

    Your thoughts,
     
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  3. Kanga

    Kanga Retired Moderator MASA Contributor

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    Yes your skimmer does this very well as well as the constant flow of water over the over flow.
     
  4. Tony

    Tony

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    Your water's surface should be agitated by powerheads to facilitate with oxygentation. The overflow and the water being sucked through the plumbing also helps in this regard and lastly as previously said the skimmer halps a lot. The hair curlers aren't necessary as they will just trap detritus with time and become a pullution problem for your water. The gentle splashing will do all the oxygenating you need
     
  5. Giepie

    Giepie

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    Like Tony said, the hair curlers is just a trap. If you look very closely to the design of a skimmer, you'll understand why it should be sufficient. Putting airstones in your DT isn't a good idead as it will create micro bubbles that look a lot like white-spot...
     
  6. trad

    trad Fish, thats the word!

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    I also dont think that the O2 levels in the water necessarily have anything to do with how many fish or corals you can keep as some books suggest. It could contribute but not the principle consideration.
     
  7. Tim S

    Tim S Thread Starter

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    Thanks for the comments, so after I had just cleaned them nicely I'll toss them.
     
  8. riyadhessa

    riyadhessa

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    Well that is a wise decision...
     
  9. Alan

    Alan Admin MASA Contributor

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    Things have changed in this hobby........very good idea to toss them out.
     
  10. leslie hempel

    leslie hempel Moderator MASA Contributor

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    just a note on the skimmer side (and perhaps this will spark debate) but i dont like to factor my skimmer in when considering my overall oxygen demand of my system, i rather look at it being able to be maintained (short term) on a static principle to allow for the worst case scenario of a power outage. i know with all the power back up systems out there these days this may seem a little medevil. but id rather look at from every average reefkeepers perspective than 1 persons who can afford the back up... the air addition from the skimmer is therefore a bonus..
     
  11. Nemos Janitor

    Nemos Janitor

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    The correct level of Oxygen is very important in a marine tank. To much and the fish get gas disease and it is required for them to osmolate, to little and filtration falls over. Remember aerobic and anaerobic filters.
     
  12. jacquesb

    jacquesb Retired Moderator

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    To add to your post, Nemo's Janitor - too little oxygen, means that the total water equilibrium is out of synch. Meaning that the water will have pH issues (increased oxygen increases pH, decreased oxygen decreases the pH), your macro algae will suffer, as will your corals, as the zooxanthellae inside the corals' cells also require oxygen to complete the task of converting nutrients into energy.....
     
  13. martin

    martin Reef Adict

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    You could sell them on the clasifieds as I am sure some of the guys could use them to tidy up their hair..........:p
     
  14. Tim S

    Tim S Thread Starter

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    Hmmm. It still sounds as if it is generally taken for granted that the oxygen level will be fine without any consious effort appart from the skimmer and surface agitation with circulation pumps?
    No one seems to be doing something ......else?
     
  15. Bob the (reef)builder

    Bob the (reef)builder

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    Correct as long as you are not going to be too wild with your stocking.

    Another factor that I have learned the hard way is that your tank should, if at all possible be wider or as wide as it is high. I makes a big difference to the proportion of air interface to water volume. This obviously gets more critical in a power outage especially with big active fish like Tangs.
     
  16. Tim S

    Tim S Thread Starter

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    Thanks for your viewpoints.
     
  17. Annoying

    Annoying

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    In my tank I use a powerhead very near to the water surface that I only switch on at night. The pumps suck the water and a funnel of air thus filling the tank at night with billions of tiny bubbles!
     
  18. Nemos Janitor

    Nemos Janitor

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    Very few aquarists monitor the DO (dissolved oxygen) in their tanks. The DO in a tank should be kept between 7ml/l and 3.5ml/l with 5ml/l being the saturation point in saline water. Things to note.

    1) Tanks with DSB experience lower DO levels at night due to high respiration rate of bacteria and critters in the sand.
    2) Algae (chaeto, caulerpa etc) consume oxygen at night due to Photosynthesis. One of the reasons for ATS lighting to be timed when the aquarium lighting is off.
    3) DSB's that are it cabinets without light will experience low DO and will underperform.
    4) DO effects PH. So aquariums that have low PH normally have low DO.
    5) Altitude effects DO due to the relative pressure. Aquariums in gauteng have a lower DO than those at the coast.
    6) Temperature effects DO the hotter the water the less DO.
    7) SG effects DO the higher the SG the lower the DO.
    8) Protein skimming removes organic compounds that consume oxygen and through the air volume used replenish, or should i say promote the CO2 exchange lifting DO.

    Now aquarist do not normally monitor DO as it is assumed that the skimmer and water surface CO2 exchange is adequate.

    IMO. Due to the effect DO has on pH, SG, Redox, Ca i feel it is important to monitor DO. Also it is important to measure your water parameters at a given DO because a change in DO can give the aquariust the impression, say PH is shifting due to calcium addition when in fact it is due to a high DO above saturation.

    Ok so now how to determin the DO. Pinpoint have a DO meter and so does Hanna on some of their Photometers and the hanna Hi9828 can measure DO. I beleave that test kits are available but none seem to be pushed by the sponsors on this site. Maybe after reading this note they will become available.
     
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  19. Stressed Eric

    Stressed Eric

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    I'd be a bit worried about creating bubbles in the main tank, it's dangerous to some fish and certainly increases salt creep - i rather rely on an algae scrubber where i can control the salt going all over and messing up lights, etc.
     
  20. jacquesb

    jacquesb Retired Moderator

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    Excellent answer Nemo's Janitor! Many thanks!
     
  21. Tim S

    Tim S Thread Starter

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    Hi Nemos Janitor

    Your quote " 2) Algae (chaeto, caulerpa etc) consume oxygen at night due to Photosynthesis. One of the reasons for ATS lighting to be timed when the aquarium lighting is off. "

    What is meant by ATS lighting? I gather it's some light form over the DT which runs after hours. Providing lighting to the DSB also came up. What would this be and would it run 24/7?
     
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