Can we rely on Test Kits?

Discussion in 'Water Parameters and Additives' started by JackSplat, 20 Dec 2013.

  1. JackSplat

    JackSplat

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    I have been using Red Sea products since I started and found them very good overall. I did have a problem with a Calcium test kit where one of the reactants was defective, causing me to chase my tail for a week or two. It turned out to be a bad batch. Red Sea kindly replaced all the reactants, which is commendable and appreciated.

    Recently I found that the magnesium levels in my tank seemed to be "stuck" at about 1360 ppm (i also use the Red Sea test kit for this). I queried this and other reefers informed me that magnesium is an element that is overall used slowly in some tanks.

    Recently I also notice some corals sulking, not extending, opening etc.

    After six weeks of the magnesium not budging I decided to get another kit, also Red Sea, my current one was almost finished anyway, and re-tested.

    The test showed a value of 1100 ppm. Retesting with the old kit, 1360 ppm. The product claim is 20ppm accuracy, this is a 260ppm difference from two supposedly identical products from the same company.

    I did notice that the nozzle on the reactant B bottle got obstructed sometimes, which indicates to me that the reactant might be crystallizing, diluting the solution. It might be prudent to shake the bottle a bit before each use I guess, I did not see any mention of this anywhere on the product though. I would guess if this is the case the test kit would get more inaccurate with time.

    These two experiences have left me a bit worried about the accuracy of test kits in general. How much can we rely on them?

    I have pushed the Mg up to 1260 ppm so far and the corals which were sulking is happy as a clam gain. Whether it was the Mg or not, I am not sure, but if not, it is quite a coincidence.
     
    Last edited: 20 Dec 2013
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  3. mandarinman

    mandarinman

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    Mag should be three times your calcium to keep corals happy
     
  4. mandarinman

    mandarinman

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    Ps if you have an sps lps dominated tank then magnesium gets used proportionately in relation to kh and calcium and can be used up just as fast as cal and kh
     
  5. RiaanP

    RiaanP Moderator

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    What is the expiry date on the test kit?

    They are there for a reason.
    :blush:
     
  6. carlosdeandrade

    carlosdeandrade

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    Test kits, hate them. Once had a huge discrepancy between a brand new PO4 salifert test kit and a hanna tesr kit. So, not even brand new kits can be trusted. Learn your animals needs by what they look like.
     
  7. JackSplat

    JackSplat Thread Starter

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    Thank you, good info!

    I checked, is 0815

    I am starting to agree with you Carlos. It is taking a bit of time to know what to look for in behavior though. You would think that for the price we pay for these kits they would be better though...
     
  8. RiaanP

    RiaanP Moderator

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    wow. Should be ok for another 8 months. :(

    I tested my tank once this year. You will eventually learn to know what is going on.
     
  9. JackSplat

    JackSplat Thread Starter

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    Cool, hopefully soon!
     
  10. RaveMan

    RaveMan

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    Valuable thread
    Very frustrating issue
    Lends credibility to the "ignorance is bliss argument "
    Whenever I need stats I just take sample to lps - preferably one whose experienced and whose show tanks confirm it
     
  11. Munky82

    Munky82

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    I have a similar problem. Kind of...
    Used a salifert kit (previously used a redsea kit but just didn't trust the results)
    Kit showed 30-40 ppm (no visible stress on livestock)
    I've was dosing no3 po4 x for about 6-7 months.
    Started below recommended dosage.
    Tested my water every week and upped the dosage.
    The reading remained constant even after a 30% water change.
    It got to a point where my no3po4x dosage was so high, I had to clean a white biofilm off the glass daily. I have a oversized skimmer so it's not that the gunk's not being removed from the tank.
    I weened my tank off the no3po4x and have been running orca bio cubes for two months using the bomb method.
    Tested my tank the day before yesterday, got the same reading.
    Think I'm gonna have a lekka testkit BBQ! killkanga
     
    Last edited: 21 Dec 2013
  12. leslie hempel

    leslie hempel Moderator MASA Contributor

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    heres another debate entirely on the topic which is also something to consider,

    Understanding Testing - Marine Aquariums South Africa

    i personally do not test my water anymore, if i were to go to sps (currently i run an LPS system) i would check alk and ph, but im pretty confident im eradicating po4 and no3 suffieciently....
     
    Last edited: 21 Dec 2013
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