Ghost Mg

[Surfzone]

Just like the title says. I got a Mg spike and I don't know where it came from. I was dosing with a doser and once I saw how high it was on the 31st of May I took Mg off the doser to let it fall on It's own now I did a 10 gallon water change with red sea salt in the blue bucket that mixes Mg to 1230 the my batch report says that it mixes to 1281. I did the water change on the 2nd of June and when I tested today well it was at 1600. I test alk daily but everything else every 3 days unless I have a reason to test something more frequent. I'm at a loss as to where this Mg is coming from. I also use Red sea test kit that don't expire until 10/2019 for Mg batch number 587

 

[Reeferdood]

What kind of dosing pump are you using?
I have seen worn out heads that have allowed solution to pass by the head if the pump stops at certain locations. Heads that have 2 rollers instead of 3 seem to happen more frequently IMHO. Also, is the dosing reservoir higher than the level of the sump? If it is, you should make sure it is lower than the waterline of the sump.
I had a similar issue years back when I had the bright idea of having my dosing pump and reservoir over my tank and I dumped a lot of solution and emptied the reservoir. Lucky for me it was low at the time..
This is just an idea and not an opinion, Randy might have a chemistry related input to add as well.

 

[Randy Holmes-Farley Verified Community Expert]

Unless your dosing solution is still getting in, the variation you are seeing are mostly, if not completely, test error. It is very common.

 

[Surfzone]

I'm using a Dos but the tea is lower than where it goes into the tank. I'm going to try purging the line into a cup and take the res. off line completely. If I'm still getting it I'll get a 3rd party to test my water for Mg

 

[Randy Holmes-Farley Verified Community Expert]

I'm using a Dos but the tea is lower than where it goes into the tank. I'm going to try purging the line into a cup and take the res. off line completely. If I'm still getting it I'll get a 3rd party to test my water for Mg

Personally, I wouldn’t agonize over it. Magnesium is very slow to deplete and typically will be ok when using a two part product to maintain alkalinity.

I absolutely guarantee the magnesium did not drop 100 ppm in a day or two.

 

[Reeferdood]

Agreed,
after looking at the swings you have noted within that timespan I would lean towards testing error.