Hanna ULR phosphate reading high the first time

https://www.triton.de/en/
OP
DVal

DVal

Active Member
View Badges
Joined
Jan 12, 2017
Messages
271
Reaction score
207
Location
Chattanooga
I think part of the issue may be the simple fact that you aren't following the manufacturer's directions.
You aren't supposed to be using two different vials for the test. Any difference in clarity between the two vials is going to skew the results. Not to mention Hanna vials are known to have different fill to lines. I know mine do....

you should be running this test with a single vial, and you should be indexing it when inserting it into the checker, so that the checker is looking at the same spot in the same vial for both parts of the test.

I bet if you actually run the test as intended, back to back to back, the results would be more consistent.
I did exactly that just now. First test gave me .08. I emptied out the vial and cleaned it and repeated the test. The second one gave me .01. I indexed the vial and inserted it exactly the same way each and every time.
 
CaliKid Flash Sale

Arabyps

Well-Known Member
View Badges
Joined
Sep 18, 2019
Messages
824
Reaction score
4,656
Location
Palm Springs, CA
I think part of the issue may be the simple fact that you aren't following the manufacturer's directions.
You aren't supposed to be using two different vials for the test. Any difference in clarity between the two vials is going to skew the results. Not to mention Hanna vials are known to have different fill to lines. I know mine do....

you should be running this test with a single vial, and you should be indexing it when inserting it into the checker, so that the checker is looking at the same spot in the same vial for both parts of the test.

I bet if you actually run the test as intended, back to back to back, the results would be more consistent.
What do you mean "indexing". I don't see any such reference in the Hanna instructions.
 

Attachments

  • IST774_10_18-1.pdf
    938.6 KB · Views: 2

LeftyReefer

Well-Known Member
View Badges
Joined
Jun 17, 2020
Messages
673
Reaction score
721
I got the ULR standard and checked it. It was spot on. Looks like the mixed sample was degrading that quickly.
What do you mean by degrading?
Aren't you mixing a new/fresh sample for each test? if so, how is anything degrading between readings?
 
CaliKid Flash Sale
OP
DVal

DVal

Active Member
View Badges
Joined
Jan 12, 2017
Messages
271
Reaction score
207
Location
Chattanooga
What do you mean by degrading?
Aren't you mixing a new/fresh sample for each test? if so, how is anything degrading between readings?

Here was one of my other replies.
Sure thing. Its the HI774 ULR checker. I fill both vials with the 10ml of tank water and one I add the reagent. Shake for 2 minutes until reagent is dissolved. I then add C1 (normal tank water) then I add C2 and hold the button to start the 3min count. Once that is read, i dont empty the vials but run them through the test again. Its right away, so I'd imagine the reagent is still good at that point. The first reading is consistently higher (under .1 though). The second test will drop down to .01-.03 typically. What is funny is that any subsequent tests with those same vials will be consistent with the lower reading. Ill run through the test 3 or 4 times and then average the readings.

Do you think that the testing vial is no longer good after that first test and that's why I'm getting lower readings OR could it be because I have microbubbles or undissolved reagent causing the higher initial reading? I do look it over to make sure it is dissolved and there are no bubbles clinging to the glass though.
Like you pointed out, I was using 2 vials. One with normal tank water and one with the mixed sample. I tried running the test 3 times and averaging the results. I noticed that the subsequent tests would be lower. I assume the mixture is degrading that quickly since I was getting different results. I've since stopped doing it that way.
 
https://www.triton.de/en/

HOW MUCH DO YOU LIKE LIVEROCK IN YOUR TANK? NOT THE AQUASCAPE, BUT THE ROCK!

  • Love it and wouldn't change it

    Votes: 187 59.9%
  • Like it ok but would try something different

    Votes: 96 30.8%
  • Don't like it at all

    Votes: 15 4.8%
  • Other (please explain)

    Votes: 14 4.5%

Online statistics

Members online
2,446
Guests online
6,480
Total visitors
8,926
Kessil
Top