wet skimming

Discussion in 'General Discussions and Advice' started by casperman, 18 Apr 2013.

  1. casperman

    casperman

    Joined:
    31 Jul 2009
    Posts:
    51
    Likes Received:
    1
    Location:
    pretoria
    Hi All

    I am new to MASA.

    A new concept for me is " wet skimming " as a method for water changes .

    The logic is to use your skimmer waste outlet tube ( if you are having one with this capability) to do water changes .

    I have a new Deltec external skimmer with this feature .

    You then skim of waste water and not just sediment or " clear water "

    My idea is to integrate this in a automatic water change device of sort .

    What is your experience with wet skimming ?
     
  2. AdS Guest




    to hide all adverts.
  3. RiaanP

    RiaanP Moderator

    Joined:
    11 Aug 2008
    Posts:
    23,157
    Likes Received:
    1,230
    Location:
    Centurion
    your salt levels will be an issue.
    If you can keep an eye on that, you should be ok.

    I will not use this method, as you rely on a lot more water being exported running very wet skimming. In my case, that will result in a flooded waste container.
     
  4. Visser

    Visser MASA Contributor

    Joined:
    21 Nov 2011
    Posts:
    2,670
    Likes Received:
    45
    Location:
    Willows,Pretoria /Brits
    Sounds like a good theory, but in reality it would be very difficult to do.
    Firstly, you wont be able to use an auto topup for RO water as the skimmed out salt water will then be replaced with fresh water & your salinity will drop very quickly.
    Secondly, it is extremely difficult to control the amount of wet skimmate your skimmer produces & you will never have a consistent amount of waterchange.

    Trust me, its better to do your normal waterchanges on a weekly or biweekly period than to have a salinity that is swinging up & down all the time.
     
    casperman likes this.
  5. cizanie

    cizanie

    Joined:
    28 May 2011
    Posts:
    137
    Likes Received:
    0
    Location:
    mossel bay, sa
    what is the difference between wet and dry skimming?
     
  6. Seabass

    Seabass

    Joined:
    28 Jul 2009
    Posts:
    2,383
    Likes Received:
    21
    Location:
    Gonubie
    Sounds like a good way to do it. Are you going to also have a auto RODI top up unit installed.

    Could have a problem with salinity if you run auto water change and auto RODI top up.

    Water removed by wet skimming will be replaced by ASW or RODI water? This might impact salinity.

    Me thinking only. Hope it turns into a great discussion.
     
  7. Seabass

    Seabass

    Joined:
    28 Jul 2009
    Posts:
    2,383
    Likes Received:
    21
    Location:
    Gonubie
    Wet, more watery.
    Dry, more particles in less water skimmed out.

    Which is better, who knows. That's not a question. I have read many threads and don't know.
     
  8. casperman

    casperman Thread Starter

    Joined:
    31 Jul 2009
    Posts:
    51
    Likes Received:
    1
    Location:
    pretoria
    Wet skimming is where you dial your skimmer so that it produces a lot of watery waste .
    The theory is that you then extract more dissolved pollutants in this way .

    You should then replace the losses with premix salt water that matches the water in salinity in your system.
    If you use R.O water you will end up with a drop in salinity.
     
  9. cizanie

    cizanie

    Joined:
    28 May 2011
    Posts:
    137
    Likes Received:
    0
    Location:
    mossel bay, sa

    is it a setting on the skimmers that can be changed or do you buy either a dry or wet skimmer?
     
  10. 459b

    459b Moderator MASA Contributor

    Joined:
    12 Mar 2008
    Posts:
    9,735
    Likes Received:
    785
    Location:
    Cape Town
    Big problem here is you cant compensate for evaporation. So by using salt water for top up you will push up the salinity.
     
    casperman likes this.
  11. Visser

    Visser MASA Contributor

    Joined:
    21 Nov 2011
    Posts:
    2,670
    Likes Received:
    45
    Location:
    Willows,Pretoria /Brits
    It is how you set your skimmer to skim.
    Wet skimming has a lot of water with the skimmate & will fill your skimmer cup very quickly.
    Dry skimming is when you set your skimmer to skim with less water. (skimmate becomes a thick brown sludge rather than a brown colored water.)
     
  12. Seabass

    Seabass

    Joined:
    28 Jul 2009
    Posts:
    2,383
    Likes Received:
    21
    Location:
    Gonubie
    Yes.
     
  13. casperman

    casperman Thread Starter

    Joined:
    31 Jul 2009
    Posts:
    51
    Likes Received:
    1
    Location:
    pretoria
    I want to add a comment or observation from my own experience.

    I will advise anyone to go for an external skimmer with a waste drain option.

    Place the skimmer outside your sump where it is clearly visible and easy to reach .
    Skimmer maintenance is crucial and better done outside . Also the skimmers with a permanent cup and drain can be cleaned in situ while still working on a daily basis.

    I am tired with all the diving into my sump and fiddling with the skimmer.
     
  14. Nemos Janitor

    Nemos Janitor

    Joined:
    7 Feb 2009
    Posts:
    8,384
    Likes Received:
    286
    Location:
    Joe's Mountain
    If you want to totally automate, consider one of these. :)

     
    Last edited by a moderator: 11 Apr 2016
  15. casperman

    casperman Thread Starter

    Joined:
    31 Jul 2009
    Posts:
    51
    Likes Received:
    1
    Location:
    pretoria
    Awesomeness!
     
  16. RiaanP

    RiaanP Moderator

    Joined:
    11 Aug 2008
    Posts:
    23,157
    Likes Received:
    1,230
    Location:
    Centurion
    Doing this setup and you will permanently loose water via skimmer and due to evaporation. The one with salt, the other without. So how will your auto top up work? Fresh RO water? Or Salt water? Or mixture? But then what relation?

    Salt level drops due to normal skimmer operation is not that hectic. But over weeks it will drop your salinity slightly. Running extremely wet skimmer and draining water constantly and that impact would definitely be bigger.

    Rather get a cup cleaner as illustrated by Nemos Janitor
     
Recent Posts

Loading...
Similar Threads - skimming Forum Date
external protein skimming General Discussions and Advice 19 Nov 2015
Gravity feed skimming Protein Skimmers, Mechanical Filtration 28 Jun 2015
Skimmer 'over skimming' ? Protein Skimmers, Mechanical Filtration 19 May 2014
Is there such a thing as "over skimming"? General Discussions and Advice 11 Dec 2013
Over Skimming General Discussions and Advice 25 Nov 2013
Protein skimmer in 450 not skimming Boyu TL450 and TL550 advice 16 Oct 2013
External Skimmer not skimming? General Discussions and Advice 19 Sep 2013