How do I do the math on red sea kit?

[DracoKat]

I am confused.. I am sure it's easy, but I am not quite getting it.
I am testing calcium, alk and mg, using Red Sea

The smaller syringe does not fill all the way to the full 1ml. it stops at .9 with a .1 air space.
So I proceed with the test per direction to get the color change point. No problem.
Now I am confused to how to determine the results..

Is there a guide for complete chemistry/math idiots to make it more easily understood?

On side note, I got the 2 part BRS today and I wanted to test before I set up the dosing.

 

[Elementalj]

On the magnesium test kit you look at how much titration you've used, so if the bottom of the plunger is at the .30 mark you've used .70 of the titration, check the chart on the back of the laminated card to see your value.

 

[Elementalj]

And as for the air pocket, as long as you've filled the syringe with the tip tightly on, you will get an air pocket and it doesn't matter. You're going by the position of the bottom of the plunger.

 

[DracoKat]

thank you. I will retake the test since I failed, lol. will come back if I still have trouble. I think it's the .1 mil air pocket that is throwing me off

 

[Pruett-nc]

Several youtube videos that explain how .

 

[Elementalj]

thank you. I will retake the test since I failed, lol. will come back if I still have trouble. I think it's the .1 mil air pocket that is throwing me off

It wigs me out sometimes too.

 

[DLHDesign]

I think it's the .1 mil air pocket that is throwing me off

This got me the first time too. So long as you go to a stable point, it doesn't really matter how much you get (as long as it's enough). The thing you are interested in is the differential.

So if you pull the plunger up to the full 1.0mL, then you would look for the plunger's end position and subtract from 1. Eg; end up on 0.40, then your reading is 0.60 - which is the number you use the compare to the chart.
For one of my tests (Mg, I think? Not sure...), I usually end up only using about 0.6mL, so I've actually taken to only filling the syringe up to the 0.8mL point (and yes - there is still a ~0.1mL air pocket from the air in the tip). Then when I titrate, I subtract my final value from 0.8 instead of 1.0. Same differential, but I'm using less of the titration fluid with each measure.

I don't really expect this to stretch the kit out any (the other ingredients will likely run out first), but I feel better about not just dumping it down the drain every time.

 

[ReeferMaddness843]

Same with Salifert kits. Took me a sec to understand that the tip, although not shown in incriments, makes up for the air pocket.

 

[Elementalj]

Same with Salifert kits. Took me a sec to understand that the tip, although not shown in incriments, makes up for the air pocket.

Correct.

 

[DracoKat]

thanks, so pretty much I am starting to where the liquid fills up to, and substract what I had used?

 

[Elementalj]

thanks, so pretty much I am starting to where the liquid fills up to, and substract what I had used?

Yep. Look at the bottom of the plunger, as in the part of the plunger that the touch the fluid should the tip not be there.

 

[ReeferMaddness843]

Even with air pocket, as long as full draw of liquid and tip submerged during draw, you're reading from the plunger position.

 

[DracoKat]

@ReeferMaddness843 now I am confused again, sorry.

If the liquid stops at .9, and the end of the plunger is at .10, with .1 air pocket, am I taking the reading from the .9 position, or the .10 position?

 

[Elementalj]

From the .10 position

 

[alyee5]

The 0.1 position. Always use the bottom of the plunger as the reading

 

[DracoKat]

ok, thank you! That makes sense to why my readings seemed off. I will retake it tomorrow to get more accurate reading