Who doses Mg?

[mpderksen]

I dose 2-part, and since the AWC went online, I haven't checked Mg (lazy tester here, guilty as charged). I was having trouble getting my Alk and Ca to stay put. I finally, thanks to a suggestion here, realized I should check Mg. It was only 1000. I got it up to 1300 in a few days using SeaChem Mg. The AWC was off this last week, since my sump cleaning last weekend meant I did a 30%+ change. I just did the full set of tests and was surprised to see the Mg was down to 1160 in one week (Red Sea test). Dropping 140mg/L in a week? Should I consider dosing? I use IO Reef Crystals, which has pretty high Mg, I thought. Could I really be consuming that much? Also, I had the GFO/ROX reactor offline, but can't see how that would matter.
SG: 1.026
Temp 77.2°F
PO4 0.00ppm, HANNA
Nitrate 0.50ppm Red Sea
Mg 1160 Red Sea
Ca 506 HANNA
Alk 8.3 Red Sea
Side note: I use equal amounts of B-Ionic 2-part, which seems to make my Ca run high. Should I reduce that part, or keep them the same?

 

[thegrun]

I would dose it up to 1350 a few times before you make the decision to dose. I used to use Red Sea Pro salt, but when I switched to Instant Ocean I needed to start dosing a little magnesium since it mixes lower in magnesium than Red Sea. Be sure to follow the directions on your magnesium test kit, it is critical that you swirl the test sample the specified duration between drops or your test results will not be accurate.

 

[j_mazzy]

isn't it possible to use epsom salt to increase Mg?

 

[mpderksen]

Who doses Mg?

I would dose it up to 1350 a few times before you make the decision to dose. I used to use Red Sea Pro salt, but when I switched to Instant Ocean I needed to start dosing a little magnesium since it mixes lower in magnesium than Red Sea. Be sure to follow the directions on your magnesium test kit, it is critical that you swirl the test sample the specified duration between drops or your test results will not be accurate.

Thanks. You've given me some solid advice over the last few years, and I always appreciate it.
I'm not completely sure where the true endpoint is with titration tests. But I am consistent the way I do it (human error can certainly happen). I have a LFS I trust, so maybe take a sample in to confirm.
Any thoughts on the "equal parts of Alk and Ca" question? I'm sort of holding off on tweaking until I nail the Mg. eg. Maybe my Ca drops when the Mg is right? I don't want to chase numbers unless they're critical. 500 isn't a Ca number that scares me, but I suspect that I'll have better color once I get it back to 420.
Experienced reefers are probably laughing and shaking their heads that I can have tanks for 5 years and still struggle with something this basic....