Red sea mag test

[Corwyn]

Hi gang,

So I switched to using the pro version of the magnesium test from Red sea. In the vid on youtube, red sea says to fill the tube to exactly 1ml with titration fluid. But in the paperwork it says that this may not happen and I should just bring the bottom of the plunger to 1ml.

My problem is that this seems to be rather inconsistent - so sometimes the fluid is at 9.2 but other times it maybe 8.9.
So how do I interpret the reading on how much titrant was used from the chart that seems to assume I started with an exact 1ml?

 

[this is me]

Ehhhh....you’re not holding it right.
If you used up the 1ml of reagent and the color is not changing, your MG is way too high.
1400-1600ppm is where you want to be.

 

[Corwyn]

Ehhhh....you’re not holding it right.
If you used up the 1ml of reagent and the color is not changing, your MG is way too high.
1400-1600ppm is where you want to be.

no no the color IS changing! My issue is from tet to test I seem to draw a different amount of titrate but it NEVER actually fills to the 1ml level The bottom of the plunger is at 1ml but the liquid is at different levels which obviously affects the calculations on the level

 

[this is me]

Did you completely submerge the tip in the reagent? You have to make sure the connection where the syringe and the tip is a tight seal or you submerge completely submerge it in the reagent. My Physics book says that it should be the same everytime.

 

[rock-n-reef]

My issue is from tet to test I seem to draw a different amount of titrate but it NEVER actually fills to the 1ml level The bottom of the plunger is at 1ml but the liquid is at different levels which obviously affects the calculations on the level

That does not affect the calculation. When the plunger is all the way at the bottom, there is some air in the syringe tip. When you pull the liquid into the syringe, this air gets collected at the top, but it is offset by the reagent that is present in the tip section. So when your plunger is at the 1 ml mark, it is natural for the reagent to be a bit below the 1 ml mark (somewhere around 0.9... depending on how big the syringe tip is). When you dispense it, it will dispense exactly 1 ml of reagent. the air pocket is pushed back to the tip, and all liquid including what was present in the tip is dispensed.

 

[Corwyn]

That does not affect the calculation. When the plunger is all the way at the bottom, there is some air in the syringe tip. When you pull the liquid into the syringe, this air gets collected at the top, but it is offset by the reagent that is present in the tip section. So when your plunger is at the 1 ml mark, it is natural for the reagent to be a bit below the 1 ml mark (somewhere around 0.9... depending on how big the syringe tip is). When you dispense it, it will dispense exactly 1 ml of reagent. the air pocket is pushed back to the tip, and all liquid including what was present in the tip is dispensed.

thanks I see how that makes sense