Hanna copper test kit doesn't change results no matter what i do??

[ReefKing101]

So i purchased the hanna copper test kit today for peace of mind in my QT tank. Tried using API but found it impossible to get an accurate results. I checked the copper first up thinking i had it at 0.50ppm it read 0.67ppm. I added another Litre of water to the 40L tank and tested again and it read 0.69ppm higher?? i was a little confused so i added another 2 litres and again it read 0.67ppm. In total i ended up adding 5 litres of extra saltwater and it still reads at 0.67ppm. Is something wrong with the tester or do you need to add a conciderable amount of water to dilute copper or something?? I just doesnt seem right. I'm positive i did everything with the test kit correctly, wiped it off, ensured minimal bubbles etc.
Thanks

 

[Jay Hemdal]

That doesn’t sound right. Try testing some copper free water.
Jay

 

[Shirak]

The H1702 high range copper tester has an accuracy of +- .05ppm so a difference of .02 from one test to the other is within it's limits of error.

 

[ReefKing101]

The H1702 high range copper tester has an accuracy of +- .05ppm so a difference of .02 from one test to the other is within it's limits of error.

But shouldn’t the ppm have lowered since I diluted with 5L of water?

 

[nereefpat]

But shouldn’t the ppm have lowered since I diluted with 5L of water?

What's the volume of the tank?

Edit: oops I see you said 40L

 

[nereefpat]

What's the volume of the tank?

Edit: oops I see you said 40L

5 Liters of 40 is 12.5%.

12.5% of 0.67 ppm is only 0.08ppm, so it could be that you are just seeing the small error of the instrument.

 

[ReefKing101]

5 Liters of 40 is 12.5%.

12.5% of 0.67 ppm is only 0.08ppm, so it could be that you are just seeing the small error of the instrument.

How much water would I need to add to bring it down to 0.50ppm? Your math is good

 

[nereefpat]

.50 is what percent of .67?
.50 = x 0.67
.50 ÷ .67 = 0.75

0.75 x 40 liters = 30 liters

So keep 30 and change out 10....rounding of course.

Edit: it might be worth checking fresh saltwater, to be sure it reads zero, as Jay recommended.

 

[Frogspon]

When I pay extra for something top of the line to make my job easier yet it only makes it harder... it goes straight back.

 

[ReefKing101]

When I pay extra for something top of the line to make my job easier yet it only makes it harder... it goes straight back.

I’d love to get my money back but not sure if I could seeing as it’s used

 

[Shirak]

I’d love to get my money back but not sure if I could seeing as it’s used

So why are you monitoring copper?
Are you treating with copper? If so the Hanna copper tester is a must IMO

 

[JumboShrimp]

Have you watched a video?... Things such as keeping the test vial absolutely free of fingerprints; dissipating micro bubbles after shaking; and even to line it up (drop it down) facing the same way each time? That might help.

 

[mdh71]

I just bought a Hanna copper tester and have been shocked at how accurate it is. I first tested the copper level after adding 6 teaspoons of Copper Power, the Hanna read 1.00. I then added 2 teaspoons and the reading was 1.32. The next reading was after another 8 teaspoons were added and the reading was 2.02. My other readings were done with water changes but followed the expected value.

The first reading I got was lower than I would have expected, but the readings are consistent with each other reading and the amount of Copper Power being added.