red sea pro magnesium precision

[fishyfish22]

So I'm testing magnesium with a fresh red sea pro test kit...
I've spent the last night testing repeatedly, each time the same.

I've been using the SR Aquaristik magnetic stirrer, so it's not a matter of me not stirring enough

rinsing with RODI water between each round

also tested with a different red sea pro kit, the trace elements

so far i've gotten 1200, 1240, 1280, 1320, 1360, 1440, 1400

i'm a quarter through a bottle of the C reagent, and I have no idea where I'm going wrong. this is from two red sea pro test kits, and the lack of precision is insane

anyone know what's up?

 

[Vinny Kreyling]

You are drying the stirrer between tests?
I am using a plastic card to level any spoon of reagent to keep that element very close each time I use it.

 

[bertoni]

I haven't used that kit, but there might be an issue with the speed of the reaction. Do they specify a waiting time between drops for the final titration?

 

[fishyfish22]

You are drying the stirrer between tests?
I am using a plastic card to level any spoon of reagent to keep that element very close each time I use it.

I do both. I clean and dry the stirrer thoroughly in between every test. and I do use a card to level out the poweder

I haven't used that kit, but there might be an issue with the speed of the reaction. Do they specify a waiting time between drops for the final titration?

nope. If anything, once it turns blue there is a chance for it to go back to purple if it sits for too long. I'm just going to try salifert this is too much stress

 

[bertoni]

The Salifert always worked for me.