Reef nutrition

Magnesium test kits?

S

sfsuphysics

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Who uses one, and how "easy" is it? I bought a RedSea one and I have to say I'm about to find the company and send them a letter about how easy it ain't.

Ok there are 3 regents you fill 2 ml of water into the container
Put 1 drop of regent A, shake for 15 seconds, repeat that 4 more times
Put 5 drops of regent B in and shake for another couple seconds. It mentions a precipitation at the bottom but I see none.
Then get a pipette fill up 1ml of regent C, and put .4ml in and shake/stir up, then put 1 drop at a time from the pipette and stir up when it turns from pink to blue you're there.. Look at how much is left in the pipette and read off the chart your magnesum level

Ok no problem, I do this as directed (more than once btw), and I start dripping, one pipette later it still hasn't turned blue... I work on pipette #2 worth... still nothing.. at this point my magnesium should be over 2000ppm according to this, and from what I understand that's an impossibility. So I'm wondering if anyone has experience with this test kit? Are they all this god damn complicated? Anything easier like calcium like add a drop and shake until it turns a color without having to measure out 3 different regents?
 
I've been using the Salifert kit. Works great. But I'm a kinda chem geek and used to finish 4 hour quantitative analysis labs in 1 hour so that I could go drink beer at the student union :D

Magnesium tests pretty much use 3 reagents. The trick is that you have to deal with the dissolved calcium before you can titrate for the magnesium.

I'm not up on all the chemistry details behind the Mg titration, but if you're supposed to get a precipate in your second step, that might be the calcium. So it could make sense that you are reading over 2000ppm if the Ca didn't get precipitated.

I think it's something like the first step is acidfication... second, tie up the calcium... third titrate the magnesium.

Is this an old kit?
 
Salifert isn't really difficult. Add 4 drops of reagent, shake and wait 30 seconds. Add 1 scoop of another reagent, shake until dissolved. Then titrate. I'd rather read the syringe than count(and remember) drops.
 
Ok, saw on the RC thread that you are using Oceanic.

Combined Mg and Ca would be over 2000ppm. This could relate to your ppt issue mentioned in your calcium reactor thread.

I did have a bucket of Oceanic(free from Patrick). I mixed it 50/50 with IO to get proper alk/Ca/Mg so I could use it up.
 
So basically I need to wait for the calcium to precipitate? Hmmm it said wait 1 minute, maybe I'll wait longer.

Eileen I'll use you as a second chance, I just have had bad luck with all sorts of "Exotic" tests, Magnesium, Silicate, Phosphate.. meh. pH, Nitrate, Ammonia, Calcium, Alk, no problem.
 
i am using both an elos and a salifert kit right now. the elos is quicker, fewer steps. the salifert more precise, more steps. i.e. with the elos its either 1100, 1200, 1300,1400 ppm...with the salifert the increments are smaller, 1130, 1160, 1190, 1220, 1250 ppm etc...
 
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