Nice Cheap DIY Overflow

Discussion in 'I made this!' started by Covey, Feb 4, 2005.

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  1. Stinger68

    Stinger68 Plankton

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    Nov 17, 2010
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    im going to make one for my 75 gal ciclid tank out of 1" to start with and see how it does i have a 30 gal trash can that im going to test it in with my bio ball filtration sump and a rio+1700 return pump i actually built them last weekend and havnt had time to glue them together i built 2 of them
    a 3/4" and a 1" if they work as claimed i will use one in my 30 gal goldfish tank i have pics and will post soon also i built a return spraybar out of 3/4
    with a oneway flow valve so if i loose power water wont back sipon into my sump and water level in main tank wont overflow my sump when it drops below the overflow tube it wont overflow my sump i think this sump might be to small for 75 gal will see.more pics to come
     

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  3. justfish

    justfish Plankton

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    Jan 24, 2011
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    inner long pipe questionn

    if i want a flow of 350 gph with a 3/4 inch pipe...how long do the inner pipe has to be?
     
  4. robert

    robert Plankton

    Joined:
    Feb 10, 2011
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    By my calculations, 3.365 in should be the minimum. So 3.5 to 4 inches would be safe.

    The flow rate of the siphon is dependent on the height of the siphon from the entrance to the siphon in the tank to the Tee fitting where it vents to the atmosphere and on the diameter of the tube.

    For example, I built a siphon out of 1/2" tubing but designed it to be 30" long. It flows about 450 gph. Now the first one I built was with 1" tubing but with the T being about level with the water line. That thing barely worked.

    Anyways, if anyone's interested, here's my derived equation:
    (3600 * PI * r^2) * sqrt(768 * y) / 231 = Flow rate in GPH
    r is the radius of the tube in inches
    y is the height of the siphon from the surface of the water to the end of the siphon at the Tee
     
  5. justfish

    justfish Plankton

    Joined:
    Jan 24, 2011
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    2
    faster?

    I made this oerflow and its 3/4 inch tube and the flow its 180gph, how can i make it faster?
     

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  6. borge

    borge Astrea Snail

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    Feb 25, 2010
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    Make it bigger.
     
  7. SammyP

    SammyP Spanish Shawl Nudibranch

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    Nov 12, 2010
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    Location:
    Springfield MO
    Get that pump yet i would like to see how it turned out
     
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  9. rc_mcwaters3

    rc_mcwaters3 Clown Trigger

    Joined:
    Dec 18, 2010
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    Location:
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    3/4 inch should produce around 400-500 GPH you could take the cap off the top to get more air and take the ball valve and put it on a 45angle vs a 90 just my 2 cents
     
  10. iforgotlah

    iforgotlah Plankton

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    Jul 19, 2010
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    ok i've finally made the design. it looks exactly like the picture below ( taken off the internet ) but it doenst seem to be working. can anyone tell me why? i've not glued them together , just wondering if thats the problem, air going in through the loose pipes and losing pressure
     

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  11. iforgotlah

    iforgotlah Plankton

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    Jul 19, 2010
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    anyone? is 1" for the piping too big? and is the check valve really necesarry?
     
  12. RPM1

    RPM1 Fire Worm

    Joined:
    Apr 8, 2010
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    Location:
    Arvada, Colorado
    Not quite sure, maybe your outlet elbow is too low. Mine is just about even with the bottom elbows. 1" shouldn't be too large as I made mine from 1 1/2 PVC and do not have an issue. Yes, the check valve is necessary to purge the air from the system. If you have air in the system it will not siphon or restart.