Does dosing Kalkwasser, reduce magnesium?

[nanoreefer23]

My tanks Magnesium has been pretty stable before. I’m using Kalk+2 from brightwell that’s supposed to contain mag. My Magnesium has dropped 100pts in a matter of weeks. I’m surprised of such a heavy drop. I used both salifert and Hanna magnesium test. Hanna showed 50 points higher at 1250 vs 1200 on salifert. Is there some chemical reaction going on with the kalk and the mag that’s dropping mag faster than coral uptake. I’ve gotvboth Magnesion-P and BRS general adjustment mag mix to raise mag above 1290 at least. Looking for 1350.

 

[rishma]

I don’t think kalk will directly interact with Mg in tank. I’ve dosed Kalk for a long time.

Mg at home tests are so inaccurate and unrepeatable in my experience that I don’t use them or trust them at all. I just dose Mg approximately based on calcium consumption.

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

 

[Randy Holmes-Farley]

Kalk+2 is not useful for dosing magnesium. It has very little in it, and what is there will not dissolve.

I suspect the drop is a good part test error, but dosing magnesium in general is appropriate.

 

[nanoreefer23]

Kalk+2 is not useful for dosing magnesium. It has very little in it, and what is there will not dissolve.

I suspect the drop is a good part test error, but dosing magnesium in general is appropriate.

Thanks, I thought I read that in a reply of yours. Hoping you can answer another question, my pH in my 12 gallon would swing from 7.8-8.3, non-photo period vs photoperiod. To try to fix this I’m using the kalk dripping method with a pH controller. Works great, but I think because of the size of the tank and probably requiring much more kalk it’s keeping my Alk at about 11.8 which is much higher than what I’m looking for which is around 9 using the red sea blue bucket. I use the same method in my other larger 33 gallon nano and works exactly like I want it to. I have a bubble Magnus Mini-Q which I can’t attach to a co2 scrubber. What solutions do I have to both keep my pH 8.2-8.3 but with the 9 Alk? Maybe some mixture of methods?