Calcium low and Magnesium low

Mogwai · Mar 22, 2022

Ok so I did my weekly 35+/-% water change yesterday. Checked All parameters and they were fine. I checked today and realized my calcium is at 380 and my Magnesium is 1200. I am confused as to why and what happen here.
Not sure what I should do.

blaxsun · Mar 22, 2022

Did you teat before or after the water change yesterday, and if after - how much after? I'd test again later tonight around the same time.

Spare time · Mar 22, 2022

What is the alk level? Do you dose anything? Have you retested the salinity of the mix or recalibrated the tester? What salt brand?

Randy Holmes-Farley · Mar 22, 2022

Low salinity will do this.

Mogwai · Mar 24, 2022

Spare time said:
What is the alk level? Do you dose anything? Have you retested the salinity of the mix or recalibrated the tester? What salt brand?

Randy Holmes-Farley said:
Low salinity will do this.

I calibrate my Refractometer after every 3-5 uses. 1.023-24 SG is where I keep my salinity.

Mogwai · Mar 24, 2022

Spare time said:
What is the alk level? Do you dose anything? Have you retested the salinity of the mix or recalibrated the tester? What salt brand?

Last i checked my dkh was 10-11. My Dkh is usually between 7 and 9 with my Calcium at 420-440 Range. Magnesium is usually @ around the 1375 to 1400 range. Not sure what happened or what's happening.

Mogwai · Mar 24, 2022

Spare time said:
What is the alk level? Do you dose anything? Have you retested the salinity of the mix or recalibrated the tester? What salt brand?

I only dose trace elements when Calcium drops below 400. I checked before the trace elements dose it was 360-380. I dosed trace elements and waited for about an hour before checking again and it was at 360-380 Range still. That was when I decided to test my Magnesium and saw that it was low for my liking. I use Reef Crystals by Instant Ocean.

Mogwai · Mar 24, 2022

Mogwai said:
Last i checked my dkh was 10-11. My Dkh is usually between 7 and 9 with my Calcium at 420-440 Range. Magnesium is usually @ around the 1375 to 1400 range. Not sure what happened or what's happening.

It can't be lack of maintenance for I do water changes every week. Almost half the display volume every week.

Dburr1014 · Mar 24, 2022

Mogwai said:
It can't be lack of maintenance for I do water changes every week. Almost half the display volume every week.

So did you recalibrate the refractometer and test again?

Mogwai · Mar 24, 2022

Dburr1014 said:
So did you recalibrate the refractometer and test again?

I have to check tomorrow before leaving for work. Haven't had the time working back to back 16hr shifts since I last checked on Tuesday.

Mogwai · Mar 24, 2022

Mogwai said:
I have to check tomorrow before leaving for work. Haven't had the time working back to back 16hr shifts since I last checked on Tuesday.

So far everything is still alive. Thank God!

Randy Holmes-Farley · Mar 24, 2022

Mogwai said:
I calibrate my Refractometer after every 3-5 uses. 1.023-24 SG is where I keep my salinity.

That is quite low and will give low calcium and magnesium. It entirely explains your low values.

Mogwai · Mar 24, 2022

Randy Holmes-Farley said:
That is quite low and will give low calcium and magnesium. It entirely explains your low values.

1.023-24 is too low? I never keep my salinity at 1.025-26 SG due to evaporation. Just in case my ATO stops working at 1.023-24 will give me enough time to correct it if it should raise higher than my initial Salinity Range. What is your recommendation for SG based on my salt mix (Reef Crystals By Instant Ocean)?

Dburr1014 · Mar 24, 2022

I get coral problems at 1.022, so you are on a fine edge.

Mogwai · Mar 24, 2022

Randy Holmes-Farley said:
That is quite low and will give low calcium and magnesium. It entirely explains your low values.

I may have to use a different salt mix. Was reading the averages of Calcium and Magnesium in the one I use and it definitely explains the low levels. Smh!!!

Randy Holmes-Farley · Mar 24, 2022

Mogwai said:
I may have to use a different salt mix. Was reading the averages of Calcium and Magnesium in the one I use and it definitely explains the low levels. Smh!!!

if you raise the salinity to 35 ppt (sg = 1.0264) the calcium and magnesium will be plenty high enough.

Mogwai · Mar 24, 2022

Dburr1014 said:
I get coral problems at 1.022, so you are on a fine edge.

Randy Holmes-Farley said:
if you raise the salinity to 35 ppt (sg = 1.0264) the calcium and magnesium will be plenty high enough.

Yeah... I'll try to slowly raise it to close to that before I buy a different salt mix. This hobby is getting more and more expensive. LOL!

Dburr1014 · Mar 24, 2022

Mogwai said:
I may have to use a different salt mix. Was reading the averages of Calcium and Magnesium in the one I use and it definitely explains the low levels. Smh!!!

IO is cheap and good salt.