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  1. #1
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    overflow and return question (plumbing)

    I was just wondering. I just started my 90g with a 30g sump. I have my overflow on a 1.5" pipe and my return on a .5" pipe. I was wondering if the return pipe should be a 1" pipe instead. I've been reading alot of people have a 1" pipe to 1.5". I was wondering this becuse in my sump from the overflow pipe I seem to be getting enough bubbles. They are getting trapped and not returning to the display tank but just wondering how I could fix this. Any help would be nice thanks.
    rayzzfish...

  2. #2
    Senior Member xenon's Avatar
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    Return pipe is usually 3/4" from what I have seen.

    The size of the pipe is fairly irrelevant because the smaller the pipe the more pressure out the end. You can also split your 1/2" pipe so that you have a 1" out in total.

    What pump are to using for return and are you currently throttling it back with a valve?
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    90g AGA Reef Ready bare bottom with 100lb of cooked Hatian LR, 40g breeder sump, Mag9.5 pump, Coralife 48" Auqualight Pro, Euro-Reef RS135, Sequence Barracuda pump, SpectraPure Maxcap RO/DI

  3. #3
    Moderator cres's Avatar
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    Whether you need a 1/2" or 2" return will depend on the pump. A pump in the 500-1000 GPH range should be on 1" or larger plumbing.

    But, undersizing your return line won't contribute to bubbles. If anything increasing the size of your return line will increase the flow and make the bubble problem worse. It will increase the flow (which is generally better and makes better use of your pump).

    There are a couple of things to try to reduce bubbles from the drain line reaching your return pump.
    1) a bubble trap (basically slows the water flow and diverts the air up)
    2) baffles in the sump (blocks some bubbles and encourages others up)
    3) move the intake of the return pump as far from the drain as possible. Maybe add an elbow to the intake of the pump so that it collects water from the bottom of the tank.
    4) raise the water level in the sump. The deeper the water the more dispersed the flow and the more likely air will rise before reaching the return pump. Just make sure you still have room for the flow back when the return pump is turned off.
    Sarchasm: The gulf between the author of sarcastic wit and the person who doesn't get it.

  4. #4
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    Quote Originally Posted by xenon
    The size of the pipe is fairly irrelevant because the smaller the pipe the more pressure out the end.
    This isn't entirely true (from what I've been told, at any rate). A smaller pipe, while creating more pressure, will also add more head as there is increased friction the entire length of the pipe. General consesus seems to be to use as large a pipe as is convinient from the pump, and reduce it at the end to increase pressure.

    For example, a mag12 with a 1.5" return pipe reduced to 3/4" at the end should result in more flow than the same pump plumbed with 3/4" all the way down. I haven't tested any of this myself yet, but there are several threads on reefcentral about it. Pressure rated pumps are a different story, of course.

    Personally, I would use at least 3/4" or preferably 1" for the returns on your 90, with a ball valve for fine tuning.

  5. #5
    Senior Member xenon's Avatar
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    Quote Originally Posted by Faerin
    This isn't entirely true (from what I've been told, at any rate). A smaller pipe, while creating more pressure, will also add more head as there is increased friction the entire length of the pipe. General consesus seems to be to use as large a pipe as is convinient from the pump, and reduce it at the end to increase pressure.

    For example, a mag12 with a 1.5" return pipe reduced to 3/4" at the end should result in more flow than the same pump plumbed with 3/4" all the way down. I haven't tested any of this myself yet, but there are several threads on reefcentral about it. Pressure rated pumps are a different story, of course.

    Personally, I would use at least 3/4" or preferably 1" for the returns on your 90, with a ball valve for fine tuning.
    Yes you are correct but the friction loss is not that significant. I would rather have more friction and more pressure because a return pipe can add flow for corals.
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    90g AGA Reef Ready bare bottom with 100lb of cooked Hatian LR, 40g breeder sump, Mag9.5 pump, Coralife 48" Auqualight Pro, Euro-Reef RS135, Sequence Barracuda pump, SpectraPure Maxcap RO/DI

  6. #6
    Moderator cres's Avatar
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    Speaking from an efficiency point of view, you should use your sump and return pump to slowly turn over the water in your tank. You should use a closed loop system or in tank pumps for the bulk of your current.

    Fighting gravity is expensive power wise.

    As Faerin says, you will get more flow from a larger pipe with a constiction at the end only. Especially as you add elbows and joints to the pipe.
    Sarchasm: The gulf between the author of sarcastic wit and the person who doesn't get it.

  7. #7
    Former Moderator a4twenty's Avatar
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    i see how this works on horizontal runs ( closed loops ) but what most people forget is to subtract the head loss for reducing at the end ( approx 27% ). in a closed loop you wouldn't need to reduce it so that would be fine. it starts getting a little grey for me when the it starts going vertical. if you take a 3/4" outlet and increase to 3" pipe you have increased the volume of water standing on the pump by 16X. gravity loss has to start canceling the decrease in friction at some point.

    the only way to know for sure will be to run some test, when i get some free time i'm going to try and see what i come up with. i'm always looking for free flow :biglaugh2
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    120S RR tank with 60G basement sump / fuge

    Return Pump: Little Giant 4-MDQX SC
    Water Movement: MP40W, Seio 1500, (2) Hydor K4's
    Lighting: 400W SE MH with 10K Venture
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  8. #8
    Former Moderator a4twenty's Avatar
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    ooops i guess i could actually contribute to the guys question :loser:

    if you want to reduce the bubbles, you can install a bubble tower, here's a pic of mine. it makes a huge difference.

    `

    120S RR tank with 60G basement sump / fuge

    Return Pump: Little Giant 4-MDQX SC
    Water Movement: MP40W, Seio 1500, (2) Hydor K4's
    Lighting: 400W SE MH with 10K Venture
    Skimmer: Euro-Reef RS250 with gate valve
    Other: RODI, RDSB, PO4/AC reactor


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  9. #9
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    On my AGA 90 (with the AGA overflow kit)- the overflow is 1 1/4" ID , the return is 3/4" ID- I just made a trip to Home Depot for vinyl tubing (the overflow kit has barb fittin75gs) and ball valves. The 3/4" is only available in a 10' lengths (can't purchase it by the foot)= 13.99$, the 1 1/4" tubing was 3.99$/foot. Also picked up stainless-steel hose clamps for each hose.

    I'll be using a Quiet One 6000 (1200 gph at 1' head pressure)- my long-winded question is this: will this work ok, or did I (again) overlook something critical?

    More information: the overflow will be +/- 50" from top of the overflow to the bottom of my sump. The return will be about the same (+/- 2")...
    Any/all help appreciated as I'd like to get the plumbing done this week in order to start filling the tank by the weekend.

    Thanks, (and apologies for the long-winded question...)

    Jean D.

  10. #10
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    Tank is filled, connections have been made and things seem to work for the most part.

    A few tips I'll remember next time with some questions as well:

    1- CLOSE the overflow ball valve when filling the tank...avoids water pouring in and over the sump tank...especially when you forget to check that the overflow is actually going INTO the sump tank...ooooooops.

    2- remember #1!

    3- Measure salinity at 1/4, 1/2, 3/4 of the way through...I'm currently sitting at 1.035 (Measured with my calibrated refractometer and hydrometer) - any thoughts on how to lower the salinity ???

    4- Test the return pump BEFORE assuming it will be quite enough...my Quiet One 6000 sounds like a major compressor running at full tilt- the name is absolutely a misnomer- unless I happen to have the single noisiest Quiet One pump to come off the assembly line??? Any replacement suggestions?

    5- Get an extra pair of hands who are able to help (my 9 month pregnant wife was willing to help, but it didn't help a whole lot

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