Metal in Reef tanks

Discussion in 'General Discussions and Advice' started by seank, 8 Mar 2009.

  1. seank

    seank

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    I know it was discussed some time ago, but this is something I need to know and always bothered me.

    Shipwrecks are 99.9% Metal. I know that the ocean is big, currents all around to dissolve the metal etc but... These Coral grow on top of the metal, and it looks as if they more beautiful than the ones growing further away, on the rock... How Come??????
     
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  3. Warr7207

    Warr7207

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    Exactly what you said, the dissolved Iron Oxide (Rust) is so diluted when in the big ocean that the coral absorbs very little, but in our tanks small volume and closed system, so the rust is there till it gets absorbed by a coral or hopefully your carbon
     
  4. Matt

    Matt MASA Contributor

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    The coral grows more rapidly on the metal because it gives of an electric current into the water... In a closed system like an aquarium the iron oxide etc etc given off by the metal will pollute the tank.
     
  5. jacquesb

    jacquesb Retired Moderator

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    Sean - this is indeed a VERY VERY interesting article. I would just LOVE to have some scientific proof on this. Where's Lappies/459b - they are some of the scientists on MASA - please let us have some more scientific information on what effect iron oxide (a.k.a rust) has on ANY of the life stock in our glass boxes? ie. invertebrate life, fish, etc?
     
  6. Reef Maniac

    Reef Maniac MASA Contributor

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    Interesting question, Sean :)

    Yes, I think that whatever dissolves would become diluted pretty quick, but the concentrations directly above the iron must be higher than further away. As Sean said, the corals are actually growing ON the metal, and are looking better than the ones growing "normally" some distance away.

    I too would like to have some scientific reasons for why this is so, but suspect that an increase in symbiotic algae living in the corals would play some role in this (iron being very limited in NSW, the dissolved iron would act as a fertilizer for the algae...).

    Of course, many of the "phosphate absorbers" we use in our tanks consist of iron oxide (rust), and they don't seem to dissolve much in the water, so I also guess that the "dissolving" (rusting) is a rather slow process, probably limited by the available oxygen in the water.

    Hopefully our resident scientists can shed more light on this...

    Hennie
     
  7. scubaninja

    scubaninja

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    from what i've studied on rustin for uni, one single piece of metal can have a positive and negative side dependin on whether or not the metal was bare as in not painted. this would set up a cell and a current would flow oxidising iron. as hennie says its limited to oxygen. i think the current might help corals, as you posted in those previous threads sean. the ones about the electric cages? i could be talkin utter nonsense though. my2c
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  8. jacquesb

    jacquesb Retired Moderator

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    I have asked Lappies to have a look at this, and give his input on this.
     
  9. Matt

    Matt MASA Contributor

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    Cool ;) I remember watching a program on TV where they put these metal cages into the sea which give off an electric current and it actually increases the speed of coral growth. Regarding the actual substances given off by the metal I am not sure of....
     
  10. Tobes

    Tobes Retired Moderator

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    Sean has a very good question here. I've seen on discovery channel that they clean old ships completely from any form of oil and chemicals - they get inspected under very high standards and strict regulations by enviromental people afterwards and then they sink them - to build artificial reefs!
     
  11. seank

    seank Thread Starter

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    Has someone found Lappies yet????? :whistling:
     
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