lets talk skimmer water depth height

Discussion in 'Protein Skimmers' started by Dingo, Jun 21, 2011.

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  1. Dingo

    Dingo Giant Squid

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    I'm no engineer so this is a stab in the dark... But could the increase be due to air and not water... Such that the decrease in energy used by the pump from pumping less head pressure is offset by the force reguired to pull the air against the pressure gradient created by the increased depth? Therefore saying that the pump uses more energy to integrate the air when there is more water flowing through the skimmer.
     
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  3. evolved

    evolved Wrasse Freak

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    Perhaps, but I see the flip side of the coin too.

    If the movement is faster, it can filter more water. Provided a sufficient dwell time in the sump skimmer chamber, it might pull more by passing the same water volume through multiple times.
     
  4. evolved

    evolved Wrasse Freak

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    See, I am an engineer; a very frustrated with myself engineer after my earlier partial flub. :p

    Still collecting my thoughts/reasoning on this...
     
  5. m2434

    m2434 Giant Squid

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    I'm no engineer either, but that was sort of what I was thinking. You have more water you need to pull the air through. I remember when we were kids, we would make snorkels. As you went deeper and deeper, it got tougher and tougher to breath through. After about 3 feet forget about it....
     
  6. artur

    artur Fire Shrimp

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    Just bought XP 1000 sss Octopus cone skimmer. Called Coralvue an asked about water level recommended. It is 5.5".That is what I do.
     
  7. salt4me

    salt4me Skunk Shrimp

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    Your moving the same amount of water wheather it sits in 6 inches or 10 inches. A 100 gph pump is gonna move 100. Now as the head increases on the pump the amp draw goes up and more power is used. A skimmer 27" tall sitting in 6" of water will pull same amps as in 10" of water. It still has to push that colum of water 27" inches. Dang don't make me split the cord on my skimmer just to test with an amp meter lol.
     
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  9. evolved

    evolved Wrasse Freak

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    That's a matter of static pressure though. Your lungs are at atmospheric pressure, and the deeper you go the greater the pressure differential becomes. Your lungs only fill with air because your intercostal muscles (and diaphragm) contract, expanding your ribcage, allowing air to come in. You get too deep, and your intercostal muscles aren't strong enough to overcome the pressure differential.

    THAT I can explain. ;)

    Power consumption is a function of both flow and head. The less head a pump has, the more flow it is capable of. Since this is not a linear relationship, this is why power consumption goes up when the skimmer pump is deeper (and has less static head).

    I think... ::)
     
  10. Powerman

    Powerman Giant Squid

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    Well you just have to be careful how you phrase it. Raising the skimmer lowers the water level in the skimmer and uses less power.... so it needs to be stated by lower skimmer depth or lower water level it is in. do you see what I mean? so yes.. the above is certainly true due to the pump moving less water due to higher back pressure.
     
  11. Powerman

    Powerman Giant Squid

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    No, actually it matters a great deal in relation to differences in water level. Normally a pump is attached to a pipe, which is really a container. A skimmer pump has no discharge piping, but there is a difference in water level between skimmer and sump which makes a difference in head pressure in relation to suction side and discharge side. Changing pump air/water output changes a skimmers performance a great deal.
     
  12. m2434

    m2434 Giant Squid

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    When the pump is deeper in the water, it has more water above it and therefore there is more static pressure pushing down on it. It would seem the pump only fills up with air because the motor is spinning, like the muscles in your lungs, it takes more energy to do so. The head pressure certainly makes a difference, but so would this statics pressure I think.

    All I know for sure is whenever I see one of these tests, more water depth = more power consumed. Of course now that I am actually looking I can't find them LOL.