Test Results - High Magnesium? Help

[CJ Monty]

I am at a lost for the life of me I can not get an accurate reading. My rea sea test kit always seemed high for magnesium 1600+ and I do not dose anything but kalk. So I bought a Salifert Test Kit. Just got finish and it registered off the chart. Used the entire 1ml syringe and it only turned purple (not the final blue).

The salifert kit is dead simple. 5 drops and one scoop then swirl. Fill syringe and swirl in between drops. The only thing I can think of is when I fill the syringe (I have the plastic tip on) and pull the bottom of the plunger to 1 ml the liquid comes up to about .82 and their is a .18 air bubble at the top. The kit indicates their will be air at the top (which makes sense because the tip contains air before you fill it up). The illustration indicates the liquid comes up to .96 which is a big difference but I do not know what I am doing wrong.

Please help!

 

[HB AL]

After the syringe empty’s suck up a little more and see how much more it takes to change to blue to give you an actual #. Not sure what’s causing it to be that high but guys that know more than me are probably gonna need more info to help ya diagnose your issue.

 

[CJ Monty]

I just did it with fresh salt water mixed (instant ocean reef crystals) to 1.026. It took about 1.35 ml to turn it blue.

 

[Bpb]

Same here. I’ve been using plain instant ocean, or a 50/50 blend of instant ocean and reef crystals, and the past maybe... 4 or 5 batches I’ve bought max out my magnesium test. Full plunger. I’ve not gone beyond that. I just know it’s 1600 ppm+. Must be something in their formula they’ve changed. I’ve tried multiple test kit lots and I stir my salt very well before using. Tank seems to be happy so I’m not worried about it.

 

[HB AL]

Sounds like the batch of salt you have. Anyway you can go to a friends or lfs and test a different salt to see if indeed it’s just your batch? What’s the calcium and alk mix up at? What does your current bag of salt say the mag should mix up to?

 

[CJ Monty]

Ok makes me feel a little better. Will test Ca tomorrow but was getting over 500 for that as well. I am fairly new to reefing and from what most salt mixes are low on Mg so was very confused and assumed user error.

 

[HB AL]

If calcium is above 500 then your mag being around 1600 sounds about right, just a little on the high side for both but not life threatening. What’s your alk?

 

[CJ Monty]

If calcium is above 500 then your mag being around 1600 sounds about right, just a little on the high side for both but not life threatening. What’s your alk?

So this is on fresh salt mix.
Mag - 1550+ - took 1.35 ml to change
Calc - 500+ - took 1.25 ml to change
kH - 9.5

I think it maybe me. I just dont know what I am doing wrong. Like I stated early when I suck up 1 ml in the titration syringe I get about .8-.82 of liquid and the top is an air bubble.

 

[Jason Albanus]

We too struggle with high Mg. It consistently rises instead of falling.

Measued new batch after mixing with Instant Ocean and got 1350. This brought the tank down to 1400. Today (two weeks later) it’s back up to 1600! Ca is 440 and KH is 3.8/10.6 - almost spot on. We dose small amounts of KH and Ca several times a week.

When testing we consider the amount of fluid used (0.8 - 0.82 in post above), not the size of the syringe (1ml).

What would cause Mg to rise instead of falling over time?