Reading API tests

Discussion in 'Water Chemistry' started by Peredhil, Nov 23, 2008.

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  1. Peredhil

    Peredhil Giant Squid

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    I'm going to run my tests in the morning, so I'm hoping this will have an answer when I get up ;)

    I have the API Reef and Saltwater test kits.

    At the end of the test, I read these from the side against the card. Sometimes, it's hard to make out which color it is.

    But if I look down through the top, it looks exactly like a particular color (usually darker and 'worse' of a number... but it makes sense I would be looking through it from a denser angle, so to speak).

    I'm wondering which, if any, of the tests are OK to look at from the top. I'm thinking they all need to be viewed from the side - it's two different values.

    Thanks
     
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  3. missionsix

    missionsix Super Moderator Staff Member

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    Some kits actually tell you to look through the top/down. Unless, your kit specifies, I wouldn't. A different shape/depth will give a different concentration. I know sometimes test kits can have a person swaying themselves into a "more positive" reading.
     
  4. Av8Bluewater

    Av8Bluewater Giant Squid

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    I can't make out anything with my API phosphate kit. It's not 0 and it's not on the other end of the scale. Very hard to discern.
     
  5. lunatik_69

    lunatik_69 Giant Squid

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    Me too!! When I test for Po4, my color is not even on the chart. It stays at a very lite green. The way that my LFS does it, is to do all the drop together instead drops.....shake....then the second drops. Hope that made sense.

    As for Peredhil's Q, if I remember correctly, all API test kits must be read from the side and not from the top looking down. Luna
     
  6. 1st time

    1st time Purple Spiny Lobster

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    I find this very stressing, I have a great eye for color as I paint but these tests!!!!---the colors are not the same. I guess it's hard to match the ink on the card to the color. LOL
     
  7. unclejed

    unclejed Whip-Lash Squid

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    Hello, I use API and I guess everyone is really talking about the Phosphate test in particular. The others I use (Nitrate, Calcium, Alkalinity) are very distinguishable color changes. On the Phosphate (especially) the color from 0.0-0.25 is very slight but look at it this way, those are the lowest results so if you think you are either one of those or in between, that isn't all that bad. Another thing I learned is to find real good light to view the results and I think that is a key. The instructions say; "view results in a well-lit area".
     
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  9. Dr.Fragenstein

    Dr.Fragenstein Panda Puffer

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    A[I's PO4 test is the only one they tell you to look down through the rest you should read from the "side". According to API you need to hold the vial, I want to say 8" away from the color chart and read in a well lit room. I always would read the color maybe 2" from chart but that is also another reason why I didn't care for API.

    Good luck
     
  10. unclejed

    unclejed Whip-Lash Squid

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    Frag, I have the card and directions in front of me (thought I had lost my mind after I read your post) and it states to read it "against" the card holding it vertically. Even shows the pic on back of card. Unless there are 2 tests, the one I have is PO43-
     
  11. Peredhil

    Peredhil Giant Squid

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    Thanks everyone. The Po4 definitely is one that is like this. I also find the PH and Nitrate test very hard to read.
     
  12. ermano

    ermano Zoanthid

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    I totally agree, i just hate reading test kits. I can never tell what color it is!!!