Help! Magnesium and Calcium very high!

[LeDart]

Help! I recently tested my parameters in my 40 gallon breeder, after not testing them for just over one and a half months, and my Magnesium is at 1600ppm, and Calcium is at 600ppm, I know I need to do a 15-20 gallon water change, but is there anything else I can do?
Parameters:
NO3: 16.5ppm
PO4: 0.29ppm
Alk: 9.0 dKH
pH: 7.9
Magnesium: 1600ppm
Calcium: 600ppm

*tested with a Hanna HI97115, no reagents are expired.

 

[LeDart]

Tank has been running since February of 2023.

 

[Randy Holmes-Farley Verified Community Expert]

have you been dosing them?

 

[LeDart]

have you been dosing them?

I have never dosed magnesium, and the last time I dosed calcium was a month or so ago. The last water change I did was on Friday, and it was the last of my salt bucket

 

[El Toro]

Whose Salt are you using?

 

[LeDart]

Whose Salt are you using?

Instant Ocean Standard (non reef crystals)

 

[bushdoc]

Salinity/sg?
If high, obviously Mg/Ca can be raised too.
If Mg was never dosed, then it is either testing error or high salinity, other causes, like issues with salt brand/quality are much less likely but possible.
Did you check params in freshly mixed salt?

 

[LeDart]

Salinity/sg?
If high, obviously Mg/Ca can be raised too.
If Mg was never dosed, then it is either testing error or high salinity, other causes, like issues with salt brand/quality are much less likely but possible.
Did you check params in freshly mixed salt?

Once I get home (3pm cst) I will test my pre mixed water, as for my salinity, 36ppt as of my last wc, but I will check again once I get home.

 

[Randy Holmes-Farley Verified Community Expert]

Calcium and magnesium do not rise on their own. The current values, whatever they may be, are not likely higher than your salt mix at the same salinity.

 

[LeDart]

My Salinity is at 36.3 ppt, I am doing a retest now to see if it was a bad test or not

 

[Randy Holmes-Farley Verified Community Expert]

With respect to magnesium, just say NO:

Just say NO to magnesium testing: RMM is born

OK, this thread has been many years in the making, and I'm posting it here since folks in the chem forum are probably already tired of all the threads relating to problematic magnesium testing. I'm going to propose a method, let's call it the Randy Magnesium Method, or RMM for short. All good...

www.reef2reef.com

 

[Mr. Roboto]

If anything I have found a higher mag level keeps some stubborn algae at bay. If the test come back still the same I would just evaluate the tank, does it not look healthy? If it is going good and your Alk is stable then just let it come down on its own, or stay high. I havent seen anything bad come from high mag or calc.

 

[LeDart]

If anything I have found a higher mag level keeps some stubborn algae at bay. If the test come back still the same I would just evaluate the tank, does it not look healthy? If it is going good and your Alk is stable then just let it come down on its own, or stay high. I havent seen anything bad come from high mag or calc.

If anything, I think it killed some of my acropora, but my torch frogspawns, and mushrooms/zoanthids look good, and actually look happy, I guess I am just getting all freaked out because of a high number, even though everything else is good/happy.

 

[Mr. Roboto]

I don't think it killed an acro... I have never seen them stress over these two numbers. Not to say that it couldn't have but in my experience I wouldn't bet on it.

 

[sheel be right]

If anything, I think it killed some of my acropora, but my torch frogspawns, and mushrooms/zoanthids look good, and actually look happy, I guess I am just getting all freaked out because of a high number, even though everything else is good/happy.

my mag is at about 1500 and acros still look good, ive had my mag jump to over 450 by accident before and the acros are still fine too.

 

[Randy Holmes-Farley Verified Community Expert]

ive had my mag jump to over 450 by accident before and the acros are still fine too.

What?

If you mean calcium, I recommend 400-550 ppm, and even higher is also unlikely to hurt corals, just increase abiotic precipitation of calcium carbonate.

 

[sheel be right]

What?

If you mean calcium, I recommend 400-550 ppm, and even higher is also unlikely to hurt corals, just increase abiotic precipitation of calcium carbonate.

oops i may have accidently said mag instead of calcium

 

[ElGordo236]

I have my calcium at 600ppm and I think is killing my wall hammer coral because is bleaching and I can see the little skeleton inside the polyp. Any tips or answers on what can I do or what is happening.

 

[Randy Holmes-Farley Verified Community Expert]

I have my calcium at 600ppm and I think is killing my wall hammer coral because is bleaching and I can see the little skeleton inside the polyp. Any tips or answers on what can I do or what is happening.

I don't think that result is from the calcium.

Are you also monitoring alkalinity and nutrients?

 

[LeDart]

I have my calcium at 600ppm and I think is killing my wall hammer coral because is bleaching and I can see the little skeleton inside the polyp. Any tips or answers on what can I do or what is happening.

I agree with Mr. Randy Holmes-Farley. When I had this problem I retested a multitude of times, and the tests all came out close to each other. I would do water change after water change, and it never improved. I then checked the TDS of my RODI water, and it turned out to be an impurity in my RODI water, I then replaced my RODI filters, and dumped my reservoir, refilled it, and retested. My calcium turned out to be that my Calcium was at normal levels of 415 ppm of calcium.