NEED TO ADD MG?

[Icedog]

I've noticed a downward trend in my tank's Mg levels over the past four months, and I'm wondering if I should add a Mg supplement or if there's something else going on.

The tank is 54 gallons and has had only fish and softies, until 10/2023. I added an anemone at the beginning of the month and two torches and a duncan near the end of the month.

A 10% water change is done once a week and I'm dosing iodine twice per week and nopox daily.

Testing was done at home via the Hanna checkers and samples were taken at the same time and sent in for ICP analysis. The chart below shows the results:



I'd noticed that the Ca was also trending downward, at least according to the ICP analysis. And that's what got me thinking that maybe adding Mg might not be the solution.

Any thoughts on what action to take would be appreciated!

 

[KrisReef]

Here's a recent thread that discusses Mg that may help you move forward?

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 Verified Community Expert]

Are you dosing calcium and alk? In what form?

 

[Icedog]

Are you dosing calcium and alk? In what form?

Not dosing calcium nor alk. Just the iodine and nopox I mentioned above.

Prior to 5/2023 the ICP tests on Mg and Ca had always been pretty stable. Mg a bit high at 1300-1400. And Ca at around 380-420.

 

[Randy Holmes-Farley Verified Community Expert]

Not dosing calcium nor alk. Just the iodine and nopox I mentioned above.

Prior to 5/2023 the ICP tests on Mg and Ca had always been pretty stable. Mg a bit high at 1300-1400. And Ca at around 380-420.

If you aren’t needing to dose calcium and alk, there is no consumption of magnesium and any changes are test error or salinity changes.

 

[Icedog]

Here's a recent thread that discusses Mg that may help you move forward?

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

Tks - love that thread and have certainly taken that into consideration. The trend downward just concerns me a bit. And with the new addition of LPS to my softie tank, I want to make sure I give them the correct environment.

 

[Icedog]

If you aren’t needing to dose calcium and alk, there is no consumption of magnesium and any changes are test error or salinity changes.

Thank you. And that brings up another question - and it may sound silly.

How do I know if/when I need to dose calcium and alk?

 

[thatmanMIKEson]

If you aren’t needing to dose calcium and alk, there is no consumption of magnesium and any changes are test error or salinity changes.

aren't you going to mention the RMM test kit

 

[thatmanMIKEson]

a good read if interested in the RMM

Thread 'Just say NO to magnesium testing: RMM is born' https://www.reef2reef.com/threads/just-say-no-to-magnesium-testing-rmm-is-born.1017528/

 

[Randy Holmes-Farley Verified Community Expert]

How do I know if/when I need to dose calcium and alk?

When the values trend down below your target.

IMO, calcium is ok at 400-550 and alk at 7-11 dKH.

If calcium is a bit low, and alk is ok, that may be due to low salinity. Aim for 35 ppt sg = 1.0264. The exact salinity is not critical, but everything moves up and down as salinity changes.

 

[Icedog]

When the values trend down below your target.

IMO, calcium is ok at 400-550 and alk at 7-11 dKH.

If calcium is a bit low, and alk is ok, that may be due to low salinity. Aim for 35 ppt sg = 1.0264. The exact salinity is not critical, but everything moves up and down as salinity changes.

Tks for holding my hand on this one, Randy. I've seen this in other posts of yours, but sometimes its hard for me to extract the info and apply it to my situation. There's so many variables, and I'm old - lol!

I'll keep the sg a bit higher and retest to see what happens. Tks again!

 

[EeyoreIsMySpiritAnimal]

You said you change roughly 5 gallons a week... What salt mix do you use and what parameters does it mix to?

 

[Icedog]

You said you change roughly 5 gallons a week... What salt mix do you use and what parameters does it mix to?

I use TM Pro Reef salt and it's supposed to mix to a pretty high Mg and Ca. And in looking back thru my records, I'd seen that I started using a new box of it (from Germany, not from Turkey) about the time that my Mg and Ca started to trend downward.

So I'm wondering if I might've gotten a bad batch??? Anyway, I'll be testing my prepared salt water to see if that's where the problem lies.

 

[EeyoreIsMySpiritAnimal]

I use TM Pro Reef salt and it's supposed to mix to a pretty high Mg and Ca. And in looking back thru my records, I'd seen that I started using a new box of it (from Germany, not from Turkey) about the time that my Mg and Ca started to trend downward.

So I'm wondering if I might've gotten a bad batch??? Anyway, I'll be testing my prepared salt water to see if that's where the problem lies.

That would be my suggestion