High Magnesium

[Ace]

Good evening,

I always seem to have high magnesium with coral pro sea salt at 35ppt. I'm dosing nothing but vinegar. My magnesium is roughly 1650 all other numbers are level. Any ideas?

 

[kschweer]

I wouldn't be too worried about magnesium at that level. Though a little high I don't think it can really hurt anything. Have you tried testing your freshly made water to see what the magnesium is? @redfishbluefish or @downbeach may be able to help out a bit more with the chemistry side than me.

 

[art13]

Mines been over 2k for a month or so, it will piss off inverts if it goes really high, but 1600-1700 shouldn't be any issue.

 

[redfishbluefish]

I have a couple questions.....FYI, the advertised level of Mag in Red Sea Coral Pro salt at 35 PPT is 1350 to 1430 mg/l.

1. What are you using to measure salinity....refractometer, swing arm hydrometer, floating hydrometer, etc?

2. What test kit are you using to measure magnesium?

 

[Ace]

I'm using Red Sea kit, I also use a calibrated before every use Red Sea refractometer.

 

[art13]

Red Sea I've found to be off, try salifert.

 

[downbeach]

What are you using to calibrate your refractometer? If plain RO/DI or distilled water, it may be off. I would use a seawater standard solution like this. The Red Sea Pro Mg kit can be a little troublesome to use, especially having to mix each of the 5 drops of the reagent A for 15 seconds between each drop and keep track of all five drops. Here is a demo.

 

[Russell Bennett]

What are you using to calibrate your refractometer? If plain RO/DI or distilled water, it may be off. I would use a seawater standard solution like this. The Red Sea Pro Mg kit can be a little troublesome to use, especially having to mix each of the 5 drops of the reagent A for 15 seconds between each drop and keep track of all five drops. Here is a demo.

I finally put the numbers 1-5 on the back of the instructions and I put reagent A on the number so I don't lose count of what drop I am on when I am counting to 15. I also hate that it is only 2 ml of water I always feel like I am a little off on the amount.

 

[Ace]

I use a calibration solution, cant recall what brand at the moment. I also do the counting trick, any usually test twice. I've been battling with this for about a year now, I may shift to salifert.

 

[art13]

i found the red sea mag kit in general to be off, i think it was like 100-200ppm off from my salifert, and verified my salifert was reading correctly with a couple fresh batches of salt. Also, 1800mg is not a big deal, but i'm pretty sure it's your test kit. I just use IO salt as i do dose my reef tank. If you don't dose and use water changes to keep your parameters, that will probably not work but the reef crystals may.