API test cylinder...who do I trust?

[ZapataInc]

I have an adjustable pipette that can go from .01 - 1ml of solution. I checked the calibration of it with distilled water at work and it calibrated correctly by measuring the weight of 1 ml of the water. I am trying to test my nitrates and decided to measure out my tank water with the pipette and put 5 ml of tank water in the cylinder...here lies my dilemma. If you notice in the picture that the water level is past the 5ml mark. Do I run the test with a true 5ml of water or do I do the water to the line like I always have?

 

[york1]

Throw it away and get salifert tests

 

[ZapataInc]

Throw it away and get salifert tests

Lol...that is not an option at the moment.

 

[civics14]

Trust the pipette

 

[york1]

If you trust the pipette then you have to trust that the test is for a true 5ml....

 

[civics14]

If you trust the pipette then you have to trust that the test is for a true 5ml....

I would think they make the test for 5 ml and due to cheap manufacturing of the curvatures resulted in what you have. Just my thoughts tho.

 

[york1]

I would think they make the test for 5 ml and due to cheap manufacturing of the curvatures resulted in what you have. Just my thoughts tho.

You might be right. I just dont have alot of trust in API products anymore in general

 

[ZapataInc]

I would think they make the test for 5 ml and due to cheap manufacturing of the curvatures resulted in what you have. Just my thoughts tho.

I was thinking that too.

 

[Steve Burton]

I think for whatever you're measuring with an API test kit it's not going to matter as long as you do it the same every time, that little bit of difference won't keep you from adjusting up or down to stay in the middle of the acceptable range considering the margin of error of these tests.

 

[Rainblood]

I would use the mark on the tube since thats what came with the kit.
But as Steve said - margin of error. The colors aren't exact anyhow...I always take my best guess at the color.
Then ask my wife.
And then ask my kids, which I put more weight on since their eyes are much younger.

 

[FutureInterest]

I would go by the tube as well. It's the intended amount. I find API tests to be ok for a baseline test and still use them from time to time.

 

[jcook54]

I would keep doing whatever it is you have been doing. @Steve Burton is on point and I typically encourage folks to shoot for consistency over a specific number. You can run through the tests you have but I would encourage the use of Salifert tests when the API run out. That being said, I still use API for pH and nitrate for my weekly tests. In my opinion they give me what I need but I do use Salifert nitrate kits when my nitrates are very low or I'm dosing.

 

[bzb]

OK here's what you should do:

1. Get a 500 mL beaker
2. Fill the cuvette to the line, pour it into the 500 mL
3. Repeat step 2 100 times
4. If it's full you're golden