Building a Weir style Overflow

Discussion in 'I made this!' started by dx7fd2, Jul 1, 2004.

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  1. Chris Jones

    Chris Jones Feather Duster

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    [quote author=JohnO link=board=DIY;num=1088694760;start=30#39 date=07/27/04 at 15:50:15]Dear Doctor,

    That was my point exactly :)   Others were saying that the flow rates would automatically match each other.  My statement was that they wouldn't and you would need to be able to control one or the other.  DX is doing this by the use of a tee section as you mentioned.

    John :)[/quote]
    True, True, but if the overflow was rated @ 750 GPH and you only had a pump that returned 500GPH to the tank, no adjustment would be necessary on either side, return or drain as the overflow will only drain with a surplus in the tank from the return pump. as i said before the 2" partition between the drain pipe area and the outside siphon area prevents the drain from running faster than the pump.
     
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  3. Redbeard

    Redbeard Spanish Shawl Nudibranch

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    Unless of course Spongebob falls into the skimmer box, then you might be cutting it close. LOL
    (sorry, I couldn't resist)
     
  4. JohnO

    JohnO Moderator

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    OK, I think I'm half way to understanding this :), thank you for your patience with me.

    Now, using your figures of 750/500 gph ( as an example only )

    Let's say that there was not a box involved but just a tube that could, and does, syphon at 750 gph. With a return of 500 gph the tank would eventually empty, right? Or at least empty until the water level reaches the bottom of the tube and air was sucked in breaking the syphon, correct?

    By introducing a box arrangement ( with partitions ) the syphon, in this example, starts and stops? In other words the water flow of the syphon isn't actually reduced, it just stops syphoning when the box empties and resumes again when the return water volume catches up. Correct?

    John

    PS. RedBeard ;D ;D ;D
     
  5. Chris Jones

    Chris Jones Feather Duster

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  6. Chris Jones

    Chris Jones Feather Duster

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    And when I get to explain what I do know about, its both fun ;D and rewarding 8)
     
  7. JohnO

    JohnO Moderator

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    Yes Doctor, it is a good feeling for me too, but now I have some more questions LOL

    What guarantee is there that the syphon will be maintained, particularly in a power outage?

    John
     
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  9. Chris Jones

    Chris Jones Feather Duster

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    This is why I DO have a drilled tank.LOL I don't trust it even if i watched it 100 times work perfectly. all it takes is once for disaster. I personally don't know why dx7 doesnt see about drilling his. if there is no other choice, well ok, but for me, I need as much piece of mind as I can get.

    and the suction point at the top of the siphon elbow attached to a power head should remove the air and fill up the tube if a bubble develops. But like I said, the one time it doesn't work due to algae growth, crab or snail blockage, a run away anemone, what have you, and mess city. >:(
     
  10. dx7fd2

    dx7fd2 Sea Dragon

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    I have done some work on sailboats in the past....
    [glow=red,2,300]Why do People always want to Drill Holes in Their Boats??[/glow]​
    ::) :eek: ::)

    I just have an aversion to putting holes in things that are big and are supposed to either hold water in or hold water out!!! ;D

    Maybe I will pay for it in the end but I have not heard of anyone having that sort of blockage in the venturi. (Not to get personal but I am on disability and really am not able to leave the house for very long anyway).

    I have thought about the generator thing and probably will go that route at least so that I can get some sort of power going, just in case!! [smiley=2thumbsup.gif]

    Ben and JohnO, you guys are great, really good discussion going on here!! BTW You can also put another bulkhead in the Weir or use two, as was suggested, if you need more water!!! [smiley=book2.gif]
     

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  11. JohnO

    JohnO Moderator

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    To let the water out so the boat don't sink :)

    John
     
  12. JohnO

    JohnO Moderator

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    Well, we certainly don't want anything to happen like that, my last tank was drilled with a corner weir and a chromis managed to jump into the weir and get stuck in the durso style drain pipe. Managed to slow the drain enough that the tank slowly filled and overflowed. Luckily(?) the water ran down a power cord and blew up the power point and fuse LOL

    John