Question about Hanna ULR Phosphorus Checker

Discussion in 'Water Chemistry' started by Toronto_Guy, Jul 30, 2012.

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  1. Toronto_Guy

    Toronto_Guy Fire Shrimp

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    I recently purchased a Hanna checker for phosphorus because I was sick of playing guessing games with the colour charts on my Elos test kit.

    The Hanna checker reported my phosphate levels to be 0.5 ppm!

    My initial reading on the Hanna checker was 184 ppb phosphorus.

    I multiplied this by 3.066 to get 564 ppb phosphate, and divided by 1000 to get 0.56 ppm phosphate. From what I can tell, my math was correct.

    This level was much higher than I anticipated. My Elos test kit reports phosphate to be in the undetectable range. The solution is nowhere near the dark blue colour you'd expect for a 0.5 reading.

    I tried the Hanna checker on my RODI top off water, and the result was undetectable. So, I don't think there is an issue with the checker.

    I was running GFO, which I stopped when I introduced bio-pellets earlier in the month (on the advice of my LFS owner). I've since started it up again (I figure there's more than enough phos in water for the bio-pellets), and I've dropped to 0.4 ppm phosphate overnight. I'm mixing up salt water and will do a 30% water change later in the day.

    Is there anything else that could account for the high phosphorus reading? I've been steadily running GFO for a year and a half, and I added a fuge about a year ago as well. I have very few nuisance algae issues. I did have a small cyano bloom in my fuge, but it hasn't spread to the DT at all.

    Thanks.
     
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  3. Thatgrimguy

    Thatgrimguy Flying Squid

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    Your math is right. What and how often do you feed. And how much of it. Food is BY FAR the highest source of phosphate in an aquarium.

    Additionally, you are much more likely to be nitrate limited for biopellets than you are to be phosphate limited. Many many users of carbon dosing and bio pellets still find GFO necessary. I think the only exception seems to be Ecoback users.

    At phosphate levels of this magnitude you should be having some algae issues around the tank... what are your observations?
     
  4. Toronto_Guy

    Toronto_Guy Fire Shrimp

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    I actually don't have any algae issues. That's why the reading was a bit of a shock to me.

    I'd have to scrape off my glass every few days, but that's about it. Other than the cyano bloom in my fuge (and that may have been related to starting up bio pellets).

    I know that most phos test kits aren't the greatest, but for the Elos to show unreadable while the Hanna showed 0.5 seemed strange.
     
  5. Thatgrimguy

    Thatgrimguy Flying Squid

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    Did you hold the button to allow for the 3 minute timer on the 2nd part of the test?
     
  6. Toronto_Guy

    Toronto_Guy Fire Shrimp

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    Yes I did.

    The actual sample once the reagent is added is only a very light blue colour. Are there any other Hanna checker owners that have experienced high phos readings? How dark does the solution usually go?

    I know that it's a different process, but on my Elos phos test kit chart, the color bar for 0.5 is actually pretty dark. I'm just wondering if the reagent in the Hanna checker gives similar results.

    I've had a bit of a bacterial bloom since adding the bio pellets, and I'm wondering if that could be throwing off the readings.

    You'd think that at 0.5 I'd have huge algae problems, at the very least.
     
  7. Thatgrimguy

    Thatgrimguy Flying Squid

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    Yes, and brown Sps... .5ppm is like beginner fowler status lol. I have to think something is off with the tester... Maybe the wrong reagant pack somehow?

    I have the phospate PPM tester, I can't see any difference in color after the test from my tank water.
     
    Last edited: Jul 31, 2012
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  9. Toronto_Guy

    Toronto_Guy Fire Shrimp

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    Just as a follow up to my issue, when the bacterial bloom went away, my phos readings went down. I was in the .08-.10 ppm range on the hanna checker, which is still high.

    I had some Kent reef carbon running in a reactor. Mine was made prior to the recalled batch, but I decided to remove it as a precaution anyway. I hadn't been surfing any reef forums for a while, so the recall was news to me.

    Anyway, the morning after I removed it, I did another phos test, and I was down to .05 ppm. That's without changing my rowaphos. Before I swapped the carbon out, my phos levels were staying consistant depsite changing my rowaphos.

    I've ordered a polyfilter to run in my sump to see if the carbon has created any heavy metal contamination in my system too.

    On the bright side... this finally may explain what happened to several of my LPS corals a while back. I lost 4 of them around the same time. My zoas and some soft corals didn't die off, but they did stop growing.

    It's interesting to note in the Kent recall notice that they say they will start to institute strict testing on batches. That basically means that they weren't doing anything before, and many other batches besides the ones they identified in the recall could have been bad.
     
  10. Thatgrimguy

    Thatgrimguy Flying Squid

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    Glad to hear you figured that out!!
     
  11. Toronto_Guy

    Toronto_Guy Fire Shrimp

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    Thanks! I'm glad to find out that I don't have the phos levels of a fresh water Oscar tank! LOL
     
  12. PghSteeler

    PghSteeler Tassled File Fish

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    Man makes me think I should start checking my phos, its the only main thing I have never tested for Im scared to know what my reading could be since I use tap water and dont run anything other thank Seachem SeaGel in a HOB filter.