Low Mg

Discussion in 'Reef Chemistry by Randy Holmes-Farley' started by thunderdood, Jan 29, 2018.

  1. reefruss

    reefruss Member

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    The test kit doesn't expire until 10/19. I suppose it could be operator error but it's a pretty simple test. I can't imagine I could screw it up that much. It has never measured in a normal range so it very well could be a bad test kit. I recently moved my sump and added 60 gallons of new water so it's not like I haven't done a water change recently.
     

  2. reefruss

    reefruss Member

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    Positive! Even if I read it backwards, at that level it would be very close to the same thing. It read 52 which puts it at 720, if it was read at 48 that makes it 780. My kit doesn't expire until 10/19 so that's not the problem. It could be operator error but it's a pretty simple test. It never has read in a normal range, I believe the most I've ever measures was 1140 ppm. I also recently moved my sump and added 60 gallons of new/additional water so it's not like I haven't made any recent water changes.
     
  3. reefruss

    reefruss Member

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    Sorry about the double post.
     
  4. beaslbob

    beaslbob Valuable Member

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    listen to others here. LOL

    that said my old 55g had magnesium of 800ppm when I started the diy two part system. It took literally pounds of Epsom salts to get it up to 1350. this also was experienced by another local with his tank.

    After that first correction the diy two part worked as advertised.

    my .02
     
    Last edited: Jan 31, 2018
  5. Randy Holmes-Farley

    Randy Holmes-Farley Reef Chemist Staff Member Team R2R R2R Supporter R2R Excellence Award Article Contributor Expert Contributor

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    Have you tried it on some new salt water?
     
  6. Randy Holmes-Farley

    Randy Holmes-Farley Reef Chemist Staff Member Team R2R R2R Supporter R2R Excellence Award Article Contributor Expert Contributor

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    If magnesium was really 800 ppm, a 10% water change with normal salt mixes would boost it 50 ppm. So normal water changes usually keep it well above that level.
     
  7. reefruss

    reefruss Member

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    I'm due to mix up a brand new 90 gallon batch, so I'll test that when it thoroughly mixed.

    What is everyone's opinion about the most accurate test out there?
     
  8. thunderdood

    thunderdood Member

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    I've only used Red Sea.
     
  9. Randy Holmes-Farley

    Randy Holmes-Farley Reef Chemist Staff Member Team R2R R2R Supporter R2R Excellence Award Article Contributor Expert Contributor

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    Most people seem happy with the Salifert magnesium kit. :)
     
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  10. reefruss

    reefruss Member

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    I'm mixing water today. It should be 1340 according to the Red Sea Coral Pro container, so we'll see.
     
  11. acabgd

    acabgd Member

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    I've had Mg in 800 ppm range while dosing too much Alk and too little Ca and doing only a few water changes in over 6 months. My Alk was over 15, Ca was around 280. All Salifert and RedSea tests. Slowly raised Mg, slowly reduced Alk dosing, letting it drift down naturally over few months and raised Ca to ~400 level. Everything was okay including Acros, although that is all in a well-established system.
     
  12. thunderdood

    thunderdood Member

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    I got my Mg up to 1320 and my Garf Bonsai looked much happier with the polyps having better extension.
     
  13. reefruss

    reefruss Member

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    Okay, the results are in. I mixed new water, came up with a 32 ppt salinity on the initial guess on the salt and tested. It should have given me a mg level of approximately 1240 ppm and my test came up at 675. I'm assuming I have a bad Salifert test kit. Time to order another, maybe I'll try Red Sea this time. I'm glad to see it's not my actual levels in the display tank.
     
  14. Randy Holmes-Farley

    Randy Holmes-Farley Reef Chemist Staff Member Team R2R R2R Supporter R2R Excellence Award Article Contributor Expert Contributor

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    Well, something is seriously off. :D
     
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  15. thunderdood

    thunderdood Member

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    Alright. Last night I checked my levels after not dosing anything anything over the weekend. My Garf Bonsai looks great again with full poylp extension. Dendro's look great with full extension although haven't been as hungry when I feed pellets the last 2 feedings. Alk was a little low so I dosed after the test results.
    Mg: 1360
    Ca: 460
    Alk: 6.3
     
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