DSB concrete blocks

Discussion in 'Biological/Natural Filtration and Deep Sand Beds' started by viper357, 19 Feb 2008.

  1. viper357

    viper357 Admin MASA Contributor

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    Perhaps someone could elaborate on why a DSB made up of aragonite (in this instance, Aquamedic aragonite) would end up turning solid, as you can see by the pics, this person's DSB had to be literally smashed with a screwdriver to remove it from the tank, it came out in solid blocks, needless to say this DSB was not performing at all.

    What causes this and what can we do to prevent it?

    [​IMG]

    [​IMG]
     
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  3. Kanga

    Kanga Retired Moderator MASA Contributor

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    Could I use a stainless steel skewer to see if mine is doing this
     
  4. viper357

    viper357 Thread Starter Admin MASA Contributor

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    I'm sure you could, or even a wooden kebab stick will do. I was really shocked when I saw this, solid blocks coming out of the tank, and I mean solid, we had to use a lot of force to break it up.
     
    Last edited: 19 Feb 2008
  5. jacquesb

    jacquesb Retired Moderator

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    Hi Dean - this is usually due to a very high alkalinity being the standard over quite a few years of running the tank. Also, a shortage of micro-critters to "stir up" the DSB and create tiny "worm holes" etc in the DSB could also be the cause of this.....
    As such - do I teem a DSB like that worthless, unfortunately....

    I think that this would be yet another reason why micro-critters is so important, and perhaps "sand-stirrers".....

    I run my alkalinity high, so I have to constantly check my DSB (in-tank as well as in-sump). BUT, one does not want to disturb your DSB otherwise it loses it's effectiveness as well.
     
  6. Mekaeel

    Mekaeel Moderator MASA Contributor

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    ive got the same problem on my system.most of my substrate has turned to rock.but my DSB is made up of 50% of the same substrate and no issues there.guess its all the little critters that are less in my display
     
  7. Kanga

    Kanga Retired Moderator MASA Contributor

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    I have the same mixed with SeaSand, and not hard patches
     
  8. jacquesb

    jacquesb Retired Moderator

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    How high is your alkalinity generically Kanga/Mekaeel?

    Also - how many tiny micro critters do you have in your tank/sump, Kanga? Many hundres/thousands? Or far less?
     
  9. Mekaeel

    Mekaeel Moderator MASA Contributor

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    hey Jacques, my alk plays around 7-9 dkh
     
  10. Kanga

    Kanga Retired Moderator MASA Contributor

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    Jacques, lots of life. dkh round 8-9 on avg
     
  11. Punk

    Punk

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    this is disturbing, especially because of the price of aragonite......... :scared:
     
  12. jacquesb

    jacquesb Retired Moderator

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    Thanks, Mekaeel!

    Thanks Kanga....

    Dean - could you get this guys alkalinity measurements as well?

    Another question - how much and how often do you guys dose ANYTHING (from baking soda, to commercial preparations) to increase alkalinity?
     
  13. irie ivan

    irie ivan MASA Contributor

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    Be careful with the white powder

    Substrate clumps for two reasons:
    As bacteria go about their business, they secrete substances which binds substrate grains together. This is more like a loose sticky clumping, easily overcome through bioturbation by microlife in th sandbed. (simple raking of a dsb is sufficient at this IMHO) This clumping is however nowhere near enough to form solid bricks.

    Solid brick like concrete blocks are generally formed by precipitation of calciumcarbonate because of high temperatures, overshooting pH or overdosing of either calcium or alkalinity.

    For a good read:

    Greenfield Kalkwasser

    http://www.reefs.org/library/aquarium_net/0797/0797_4.html
     
  14. jacquesb

    jacquesb Retired Moderator

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    Many thanks Ivan. So I had it partly right! Cool!
     
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