experiences with gfo overdose

Discussion in 'Water Chemistry' started by Dingo, Feb 13, 2011.

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  1. Dingo

    Dingo Giant Squid

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    I have been running my gfo more aggressively than usual the past 2 weeks to rid myself of some gha that popped up after xmas vacation due to the auto feeder putting WAYYY to much food in every day.

    Now a a select few of my acros (red planet and tricolor stag) have really lightened up in color. Im thinking its related?

    What are your experiences with over-using gfo?
     
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  3. steve wright

    steve wright Super Moderator Staff Member

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    similar to you Dingo
    but not with SPS corals
    because I had the same experience with LPS corals some time ago
    I had an elegance and a hammer coral that both almost bleached (retained very little green) after my 1st introduction of a GFO media into a softie dominated tank with GHA

    So with my SPS tank, I tend to run less than the instructions indicate and change it more frequently

    once levels are low, then keeping them low is not an issue IME
    Its the rapid reduction of phosphates over a short period that caused my LPS to lose Zoo's IMHO

    Steve
     
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  4. 2in10

    2in10 Super Moderator Staff Member

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    You probably are right since the timing matches. The corals will come back just like with photo shock. I wonder if I did while I was photo shocking my coral and everything else. I never did reduce my GFO just the lighting schedule and bulbs used. I wish I could help more on this. I do have a Red Planet that bleached as soon as I put it in the tank. It is slowly recovering its color still 2 months later.
     
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  5. 2in10

    2in10 Super Moderator Staff Member

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    I think this is a very valid hypothesis Steve.
     
  6. AZDesertRat

    AZDesertRat Giant Squid

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    Its well known and documented that running too much GFO bleaches hard corals. You should run 1 tablespoon per 10 gallons of tank water full dose and half that when first starting out so you don't shock the system.
     
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  7. Dingo

    Dingo Giant Squid

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    thanks everyone! this all sounds pretty consistent.

    My typical usage is 5 tablespoons to 120g total volume. After the nutrients built up over break I bumped it up to 7 tablespoons without any coloration problems and with only a minimal reduction in algae. So then just a few days ago I changed it out with 9 tablespoons for loss of color in only select corals and noticeable algae reduction... maybe too much of a bump this last time?

    Now should just let this batch run its course or should I remove a few tablespoons?
     
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  9. steve wright

    steve wright Super Moderator Staff Member

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    Dingo

    I cant say based on any experience what might happen if you reduce the amount you have in

    I can say that GFO works pretty quick IME and as such if its been in a couple of days, it may well have already done any harm (short term and reversable IME) that it might have done

    I would monitor my corals and see if the fading gets worse - if it does then I would reduce by 50% the GFO I had in

    in the mean time I would follow the technique that applies to carbon dosers with fading coral and dose an ammino acid based supplement to compensate for the utra low level of PO4 already caused by the GFO


    also - I know you are a frequent water tester, but pay close attention to your DKH as excess GFO can cause this to drop based on my research on the subject.

    Steve
     
    Last edited: Feb 13, 2011
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  10. Pickupman66

    Pickupman66 Tassled File Fish

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    I overdosed my gfo and stripped the water to below .01ppm phosphate. I ended up with burnt tips on my acro's and little to no polyp extension. they were NOT happy.
     
  11. unclejed

    unclejed Whip-Lash Squid

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    This thread has been interesting. I did some searching and research and found no evidence that GFO over dose (what ever "over dose" means) does any harm to coral or anything else for that matter. Always willing to learn, someone give me an article or paper on it and I will appreciate it.
     
  12. m2434

    m2434 Giant Squid

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    "Well documented" refers to reports by hobbyists, there are many.
    I don't think Scientific research is too interested in our hobby, unfortunately. Randy Holmes-Farley discusses GFO induced bleaching a bit in this article. While there probably isn't scientific research regarding exactly this topic, relating to our hobby, I think there is plenty of scientific research on the topics he discusses in this article.


    Iron Oxide Hydroxide (GFO) Phosphate Binders by Randy Holmes-Farley - Reefkeeping.com
     
    Last edited: Feb 16, 2011
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