Should I care that my mg is 1620?

hllb · Oct 12, 2019

My Mg seems to run high lately - slightly over 1600. Should I care? Any idea of cause? Tested with Red Sea pro.

salinity: 1.025
Ph: 8.1
Nitrates: 2.5
Po4: .055
Cal: 385 (working on raising this using Seachem Reef Complete)
Alk: 9.3

I’m thinking I shouldn’t care but am curious how the Mg can be that high. I’m not dosing Mg (I’ve only dosed the Seachem twice. ) water was initially IO salt but the last few wcs were with Reef Crystals

Nano sapiens · Oct 13, 2019

No salt including IO should have such high Mg. Mg is not that easy to test accurately and I've had a few inaccurate test kits over the years. I'd first check the level with a second kit (or take a water sample to your local LFS) before trusting your reading.

Rilo · Oct 13, 2019

Are you sure you're testing correctly? I mix my water with reef crystals and always get 1360 ppm magnesium

hllb · Oct 13, 2019

I am testing correctly, but I agree it seems wrong. I don’t have another Mg test though. Is there a better one than Red Sea?

CivicS14 · Oct 13, 2019

My mg is at 1600 for months now, doesn’t seem to have any harmful effect from what I can tell. Sure, I would like to get it down but why bother if nothing seems hurt by it.

rainmaker · Oct 13, 2019

You may want to stir your bucket of salt also
Was my first thought sense you don’t dose

hllb · Oct 13, 2019

rainmaker said:
You may want to stir your bucket of salt also
Was my first thought sense you don’t dose

I wonder about that too. Suggestions on how to do that? I made a pretty half-hearted attempt lol.

hllb · Oct 13, 2019

I’ll be mixing up fresh water today so I’ll test that.

rainmaker · Oct 13, 2019

I just roll bucket and Shake upside down then take a scoop and stir some more

hllb · Oct 13, 2019

Ok maybe I have a bad test kit? New water tested at 450 for Ca and 2400 for Mg. What the heck? I had to use 1.2 ml to hit the color change. That makes no sense.
In reading the directions, it talks about how you measure to the plunger as the tip holds Reagan’s and it says typically the liquid will look short .1 to .15 ml. Mine is routinely short .2 ml on the dot. Is that strange? The calcium test is typically short .15 ml as expected. It makes me wonder if I’m putting in less reagent than I think.

Follow up question: how do you wash your jars and cuvettes? I rinse with 0 TDS water but still get a film inside some of them. I did see a BRS tip of rinsing them then storing filled with RODI water. Is that what most do? How do I get them fully clean first? 50/50 water and vinegar soak?

hllb · Oct 13, 2019

Does water temp affect an mg test? My freshly mixed water is room temperature.

stanleo · Oct 13, 2019

i use Reef Crystals and my mg is high like that, even with the fresh mix. They have been for a while and I haven't had issues at all. It was suggested that I stir up the salt before I mix it with the water to more evenly distribute the elements in the salt throughout the bag. I was also told that reef crystals usually runs high. As for in the long run if mg that high is bad, I hope not.

Waynerock · Oct 13, 2019

I keep my mag pretty high, it just kinda stays that way even though I dose cal and ak every day mag just stays up there. Corals can handle a slow climb up or down and high mag keeps the hair algae fairy away.

hllb · Oct 13, 2019

stanleo said:
i use Reef Crystals and my mg is high like that, even with the fresh mix. They have been for a while and I haven't had issues at all. It was suggested that I stir up the salt before I mix it with the water to more evenly distribute the elements in the salt throughout the bag. I was also told that reef crystals usually runs high. As for in the long run if mg that high is bad, I hope not.

2400 for fresh mixed seems absurdly high, no?

I just spent some time mixing the salt and will make up some fresh water this afternoon.

stanleo · Oct 13, 2019

hllb said:
2400 for fresh mixed seems absurdly high, no?

I just spent some time mixing the salt and will make up some fresh water this afternoon.

I mixed fresh and did 1:1 fresh saltwater to fresh RO water and tested that and got a more accurate reading. Mine tests at 1680ppm. I'm going to stir up my salt before adding it to the water from now on and when I get through this case of salt I'm going to switch to a new more consistent salt.

hllb · Oct 13, 2019

Mixed the salt, made it with fresh RODI water at 0 TDS..:and it still tests at 2400 for Mg. I ordered a salifert test to compare. SG is 1.025 and I checked the calibration and it was correct (using 35 solution, not rodi)

DSC reef · Oct 13, 2019

I would try the salifert magnesium test kit. I'm betting it's a bad kit. Also, take a sample to a LFS and have them test it as well.

hllb · Oct 13, 2019

DSC reef said:
I would try the salifert magnesium test kit. I'm betting it's a bad kit. Also, take a sample to a LFS and have them test it as well.

It’s so weird. I even cleaned out the vial with a q tip to get any residue out using rodi water. Salifert will be here tomorrow and if that shows high, I’ll take a sample in.