Magnesium dropping fast

[Sailfinguy21]

My magnesium was 1080 and it killed a hawkins acropora and almost 2 others.. but they are healing now that i did 2 50% water changes with reef crystals.

My mag was 1350 after. 24 hrs later it was 1320. Now today 48 hrs later its 1290.

My alk is stable at 10 it hasnt gone down in 48 hrs. Calcium is 460 it hasnt gone down either.. but mag is dropping fast.

I thought magnesium goes down slowely compared to calc and alk ?

 

[rkpetersen]

Do you dose 2 part or use kalkwasser?
If so, you may need to supplement magnesium separately.
Do you have a lot of montis? Coralline algae?
Both can be heavy consumers of magnesium.

 

[Sailfinguy21]

My tank is mostly sps and lps. I have a bunch of montis and acros and torch and 4 bubble corals one the size of a basketball. But most of my sps corals are about golfball sized.

I have a fist sized plating red monti, purple and green. I have some ecrusting montis ect ect

Not much coraline and the coraline i have is green coraline lol.

I dont use any kalk or whatever that is.. i litterally did 2 25% water changes brought my mag from 1080 to 1350 and in 48 hrs it went to 1290.

I do have a 2 part dose i use from seachem if cal and alk go down bur i havent used them in weeks now as i didnt need too.

Frustrated i dumped 1000mL of a BRS magnesium mixture in the tank mag is 1410 now went up a little higher then i wanted.. But well see if this drops as well.

I do use activated carbon but that doesnt remove magnesium does it ?


Side note i have a star fish i want to put in my tank its in QT right now.. you dont think 1410 is going to hurt it do you ?

 

[rkpetersen]

Montis are probably consuming mag.
Might be time to consider supplementing it.
Kalkwasser is calcium hydroxide; supplements calcium and alk but no mag or other elements.
Activated carbon won't remove magnesium.
I supplement magnesium on my 2 DTs; I use the ESV brand.
My mag levels is generally in the 1400 to 1440 range.
Quite a few fromia tile stars and also serpent stars in one tank; they do fine.
Hundreds of micro brittle stars in the other tank; no larger stars there because there are a pair of Harlequin shrimp.

 

[Sailfinguy21]

Well like i said i put in 1200ml of premixed brs stuff it did raise it by like 100ppm.

I just need to buy the powder and mix it myself . I bought this 1800ml bottle from a local store premixed.. not knowing it takes s crap ton of mag mix to raise levels up even a little. So i got ripped off.

Oh well. Just suprised my mag goes down so fast i read it goes down slow.. and takes calcium with it.. my cal is staying the same