Alkalinity Test Kit Roundup

Discussion in 'Other Reef Talk' started by Eight, May 27, 2009.

  1. Roc

    Roc Guest

    Just as a side note, My API test kit was reading almost 5. DKH off, it could have been the kit, but the massive amount of complaints I found while researching on the web seem to defend the position that they can't be trusted.

    I also used some of the Sailfert calibration fluid on the API and found that it gave me a different reading each of the 4 times I tried it, however both the lemontte kit (not included in your write up, but my personal favorite) and the sailfert came back with the same readings from the calibration fluid each time and they were both spot on.
  2. Eight

    Eight Guest

    Josh, I like Tom's hardware too! Although I tend to prefer Anandtech usually...

    Your statement totally echoes what I was thinking after I wrote the original post. I think the industry could really benefit from objective reviewing of products.

    At first I was hesitant to bother with the KH test kit roundup since it's so hard to comment on accuracy or consistency, but I think just being able to show the reagents and talk about the test process/ease of use gives people much more insight into what they are buying in the little cardboard box.

    If BAR ever decides to fund test kits for a different test, like Mg or Ca, I'd be happy to write them up.
  3. tuberider

    tuberider Guest

    I've found API kits to be the opposite, rock solid, not the most accurate when dealing with higher alk levels, but very consistent. Perhaps you were getting some interference when your levels were off.

    One thing to keep in mind is that most of these companies are not making their own reagents, they farm those out to chem companies or just outright buy them. For example Hach makes the reagent for API, Hagen, and IIRC Lamotte.
  4. GreshamH

    GreshamH Guest

    I'm pretty sure Lamotte is like Omega and Cole Palmer, they don't actually make anything but rather relabel.

    The problem with people writing up test kits is we all have our own touch to not only reading but actual titration. Depending on how hard how hard you squeeze it out of the bottle helps determine the droplet size IME. This is why Norm's method of using a syringe for all titration is the best way of dealing with that issue. Maybe rather then using the actual test kit you use his method and their reagents.

    I throw down for some kits but only if you do a TON of tests, 20-30, so we have a large data field to work with :) I bet Max and other LFS would help fund this ;) I'll get you standards to test from.
  5. Eight

    Eight Guest

    Norm, can you describe what you mean by using the API reagents with the Salifert hardware? From what Gresh writes it sounds like you actually titrate using the API KH drops?

    How do you know how much KH reagent corresponds to what dKH using the API reagent?
  6. sfsuphysics

    sfsuphysics Supporting Member

    I think what Norman means is he uses the chemicals from the API test, but the dropper with the smaller precision from Salifert syringe, since you can't always expect the exact same drop size to come out of the bottle every squeeze. So if you already have a syringe with 1/10(??) mL precision just buy the API kits.
  7. GreshamH

    GreshamH Guest

    That is my understanding as well, and one that makes the most sense. I do hate the little tip on the Salifert though. After the first use I put it all back into the box and SMASHED the little tip. Good thing I have a sister that is a DVM and not to mention I also have a large amount of various sized syringes from previous jobs.
  8. Eight

    Eight Guest


    Are drops the same regardless of how they are produced?

    i.e.: Are the drops that come out of the 1ML Salifert syringe theoretically the same size as the ones that come out of the API bottle?

    If they are the same, just more consistent, then I understand why you'd use the Salifert hardware with the API reagents... if they are not, then doesn't it throw the whole test off?
  9. GreshamH

    GreshamH Guest

    technically from what I have read all drops are uniform BUT if you change the velocity of which pushed out IME you can change the actual amount in the drop. I weighed well over 300 drops on our scale at work (.001 gram) from RN bottles to see how accurate the drop rate is and while close, it does very. I suspected this was due to the uneven pressured applied to the series of bottles presses. With RN products it's not enough to worry about but with test kits it would be IMO. Using a syringe it's easier to apply a uniform pressure since you have something to gauge the pressure by (the scale on the side). The bottle you have to have the right touch every time, which most likely isn't what others would have.
  10. sfsuphysics

    sfsuphysics Supporting Member

    I wouldn't count on the drops always being exactly uniform... what if there's a tad more airflow in the room at the moment you squeeze one out (yeah that sounds nasty), well you could get a drop that's not the same, or something that I hate when I squeezing into the test tube and I hit the inside, well that's going to get a less than ideal drop size as well... HOWEVER, with the syringe you have a scale on the syringe, so it doesn't matter if it's the same size or not because when you get the color change you simply read off the syringe how much you squirted out. :)
  11. GreshamH

    GreshamH Guest

    :lol: sorry I had to does sound nasty :p
  12. Mr. Ugly

    Mr. Ugly Past President


    Pretty much what Mike said.

    It was in the link that I posted:

    Titrate using the salifert syringe and vial but with API reagents.

    I made an alk standard for calibrating.

    That way you get the low cost of the API kit, with the precision of Salifert, and the accuracy of your own calibration :D
  13. Mr. Ugly

    Mr. Ugly Past President

    More info:
  14. Mr. Ugly

    Mr. Ugly Past President

    And here:

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