Magnesium level will not rise despite my dosing

[pboutin]

I have a 160 gal total volume system
Alk 9 ppm
Cal 420 ppm
Mag 900 ppm

I use Red Sea Pro salt mix that has these params when mixed to a salinity of 35 ppt:
35.0 ppt Salinity
8.2 – 8.4 pH
12.3 - 12.7 Alk
455 - 475 Cal
1360 - 1420 Mg
390 - 410 K

The system has only been up for 4 or so months, I've been dosing Mag since early on in this tank as it's been low the highest it's been was around 1040 ppm. I dose the BRS Mag mix which I mix according to the directions on the side of their supplement containers, which says 5 cups of Magnesium Chloride hexahydrate and 3 cups of Magnesium Sulfate mixed to a level of 1 gal with RODI water. (Although they say in their video it's 7 1/4 to 3/4 cup ratio to the 1 gal total mix. (I'm inquiring about this discrepancy with BRS in another post))

I don't have a lot of coral but yet my dosing has increased as my testing shows it's been dropping. I'm up to dosing 720 ml in a 24 hour period on a dosing pump. My schedule is to run the pump for 10 min every 20 min on a 1.5 ml a min pump.

I just did a 20% water change (~40 gal) over the weekend and you would think that the level would come back up near normal.

Is it safe to dose this much and why don't I see a change in my levels?

 

[Randy Holmes-Farley]

I suspect a testing error. 900 ppm magnesium sounds very unlikely and is extremely uncommon.

That said, magnesium boosting takes a massive amount.

There's no disputing the 7.25 to 0.75 ratio for boosting. I designed it. lol

Other ratios (which I also designed) are for other purposes, such as using as part of a DIY two part. That's a 5:3 ratio.

 

[pboutin]

I suspect a testing error. 900 ppm magnesium sounds very unlikely and is extremely uncommon.

You would think then that after a large manual dose even a bad test kit would register a change. It's almost time for me to order a refill on my test kit. I'll have to see what new titration will read. I'll test my fresh salt water to see what I get.

That said, magnesium boosting takes a massive amount.

So my dosing at this rate is OK?

There's no disputing the 7.25 to 0.75 ratio for boosting. I designed it. lol

Other ratios (which I also designed) are for other purposes, such as using as part of a DIY two part. That's a 5:3 ratio.

So it seems BRS uses both ratios the 5:3 on the mixing container and the 7.25:0.75 in their videos. Which should I follow?

 

[Randy Holmes-Farley]

You would think then that after a large manual dose even a bad test kit would register a change. It's almost time for me to order a refill on my test kit. I'll have to see what new titration will read. I'll test my fresh salt water to see what I get.


So my dosing at this rate is OK?


So it seems BRS uses both ratios the 5:3 on the mixing container and the 7.25:0.75 in their videos. Which should I follow?

Use the 5:3 when dosing the two part, at the prescribed rate (independent of apparent "need" for magnesium).

Use the other ratio when making substantial boosts to magnesium and not using the DIY two part.

 

[pboutin]

So just a follow up and another question.
I replaced my Mg test kit with a refill from Red Sea. Now because of my previous dosing to raise Mg levels My Mg is off the scale I can't measure it as it's too high. The test kit only measures up to 1600 ppm. Even after a water change it's still above 1600. Is this a concern? I've obviously stopped dosing and I've also noticed my Cal level creeping up. I've slowed down my dosing on Cal to bring that back inline. I have a few corals that seem to have closed up. My concern is that the high levels of Mg might be bad.
All my other parameters are where they should be.
Alk 10
Cal 480
Mg 1600 +
NO3 4
PO4 0.04

 

[mkutsch]

You could also fill 25% of a small bucket with RODI and pretty much fill the water with aragonite. From there, top off the tank with it (cloudy water due to substrate). Now, this might work, and could have some adverse effects, like a raised kH, pH, or Calsium, but in all likelihood, it won't be detrimental. Test this water first.

I've done it before to raise some trace elements w/o dosing. It works sometimes.

Get a new test kit!

 

[mkutsch]

And your calcium is rather high..

 

[pboutin]

You could also fill 25% of a small bucket with RODI and pretty much fill the water with aragonite. From there, top off the tank with it (cloudy water due to substrate). Now, this might work, and could have some adverse effects, like a raised kH, pH, or Calsium, but in all likelihood, it won't be detrimental. Test this water first.

I've done it before to raise some trace elements w/o dosing. It works sometimes.

What will this do?

Get a new test kit!

I did get a new test kit, that's why i'm now seeing my Mg is way too high whereas the old kit said it was way too low.

 

[mkutsch]

Haven't cared eniugh to actually look into it but at first did it as an accident and it worked...