Top up Question

Discussion in 'General Discussions and Advice' started by Singularity, 3 Feb 2010.

  1. Singularity

    Singularity Hmmm amper!

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    Hi there
    Just a question i have been wondering about...
    Water taken out by a skimmer, could this affect the salinty of a tank, over a period of a month or so and when using ATO. Or would the change be to small to make a difference ?
     
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  3. mariusmeyer

    mariusmeyer

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    Tagging along here.
     
  4. jacquesb

    jacquesb Retired Moderator

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    Singularity - this depends on how big your skimmer is and how much water your skimmer removes at a time....

    My Bubble Magus BM-260 (when both pumps are running correctly - with pin wheel impellers), removes 25 litres a week of tank water (with extremely thick stinky muck) when I set the skimmer dry....

    When I set it wet, it removes 25 litres of tank water a day....

    So - YES. You HAVE to replace this with salt water..... else the topup RO water would make the tank hypo-saline...
     
  5. lIghty

    lIghty

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    IMHO it would be so small to even bother, I've yet to see any effect.
     
  6. OP
    Singularity

    Singularity Hmmm amper!

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    OK thanks Jaques. So do you just add 25L saltwater over a week to replace the skimmed water and let your ATO go about its bussines ?
     
  7. jacquesb

    jacquesb Retired Moderator

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    Yes Singularity..... But, as lIghty said - this is all relative. It depends on how much water your loose through your skimmate.

    I don't do water changes - I just constantly replace my water...
     
  8. OP
    Singularity

    Singularity Hmmm amper!

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    Guess the best would be to keep checking salinty when you first start up between water changes, i only thought this could be a problem because i am going to run a huge skimmer on a relatively small tank.
     
  9. Reef Maniac

    Reef Maniac

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    As Jacquesb said, it depends on the size of the skimmer, and on how wet it is running - and if I could add: on the ratio of the skimmer size vs the tank size.

    My Deltec AP902 removes about 1 liter of skimmate a week (running quite dry), and the total water volume of the system is about 1000 liters - that does not make any measurable difference to the salinity. I do know of a few tanks where the skimmer is run so whet that it removes nearly 20 liters of skimmate per week, and in these cases it would have an effect, especially long-term.

    Correct - check regularly for the first few months, and once you know for sure you could relax, or keep on compensating, as required. I have heard of systems that run both fresh (RO) water AND brine (salinity +40 ppt) reservoirs with a conductivity controller to compensate for salinity changes, but have never personally experienced the need for one.

    Hennie
     
  10. mandarinman

    mandarinman

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    each system is different , as long as you are doing waterchanges on a weekly basis it shouldnt be a problem, if your salinity gets a little low add a little extra water when doing topup and let it(tank water)evapourate to the correct salinity.
     

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