Be careful of dual returns

Discussion in 'Equipment' started by rygh, Jul 11, 2018.

  1. rygh

    rygh BOD

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    Quite a few people have dual return pumps and lines. I do.
    Since pumps fail fairly regularly, it really reduces risk to have the extra redundancy.

    But: If one pump dies or is turned off, remember that it can siphon back.
    And it siphons back to the return area of the sump, which may be separate from skimmers and such.

    That happened to me.
    One pump was happily pushing water from sump to DT.
    One pump was off, and siphoning almost as much water back from DT to sump.
    So a very limited amount of water was going over overflow and through skimmer.

    Something to think about when designing your setup.
     
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  2. sfsuphysics

    sfsuphysics Supporting Member

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    That's kind of funny, you set up a system to break a siphon super earlier, but because you have a second pump the water never gets low enough to break a siphon.

    That said, have no need for dual returns, now two pumps in the sump, one for return one for a manifold to "power" everything that needs water sure, and if it's the same type of pump you can always swap it over if the original pump fails in some way.
     
  3. tankguy

    tankguy BOD

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    I have always only used 1 pump
     
  4. Flagg37

    Flagg37 Colorado member

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    Sounds like a job for a flow monitor. You don’t use an apex though do you?
     
  5. sfsuphysics

    sfsuphysics Supporting Member

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    Flow monitor, or put the pump on an outlet so you can detect if current is flowing. Although there really is no reason to put a return pump on a controllable outlet.
     
  6. JVU

    JVU BOD

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    Thanks for the reminder about that.

    Some people use one-way valves, but those can cause their own problems.

    I agree having an alarm when one of the pumps fail is very helpful, Apex makes that easy but not cheap.
     
  7. rygh

    rygh BOD

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    Agree you don't "Need" dual pumps. And ironically, it doubles the chance of a pump failing.
    But I strive very hard to have no single-point-of-failure type problems that can kill everything.
    Given that heaters and filtration are in sump, a failed return pump can.
     
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  8. Wlachnit

    Wlachnit Vice President

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    I used a single Reeflo Dart pump for almost 10y....with never a problem. I switched to two DC pumps and sure enough...one of my Vectra L1 failed within 2y. They honored the warranty but was without one of my return pumps for a couple of weeks.
     
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  9. Flagg37

    Flagg37 Colorado member

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    That’s one of the advantages of the dual pump setup though. If one does go out then you’ve still got the other one moving water. But like @rygh said, there’s got to still be safeguards in place.
     

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