Magnesium

FRANK48 · May 10, 2021

NeonRabbit221B said:
What do you measure salinity with? Are you testing it with a calibration solution?

I’m using a refractometer

FRANK48 · May 10, 2021

DDenny said:
Like everyone else has stated what salt are you using to make new saltwater? Are you using a calibrated refractometer or other tool?

Salt is iquatics pro

NeonRabbit221B · May 10, 2021

FRANK48 said:
I’m using a refractometer

And calibrating it by...?

FRANK48 · May 10, 2021

NeonRabbit221B said:
And calibrating it by...?

What does that mean?

NeonRabbit221B · May 10, 2021

FRANK48 said:
What does that mean?

Use a reference solution to adjust the reading to a known salinity. Without calibrating a refractometer you are likely running very low salinity. You can buy a solution on Amazon.

FRANK48 · May 10, 2021

NeonRabbit221B said:
Use a reference solution to adjust the reading to a known salinity. Without calibrating a refractometer you are likely running very low salinity. You can buy a solution on Amazon.

Would this help magnesium?

fachatga · May 10, 2021

If your salinity is very low because your not using enough salt mixture due to testing error then it can be the problem since most salt mixes have plenty of magnesium and there where your tank will get most if not all of it from. So good to make sure you’re measuring it correctly.

FRANK48 · May 10, 2021

fachatga said:
If your salinity is very low because your not using enough salt mixture due to testing error then it can be the problem since most salt mixes have plenty of magnesium and there where your tank will get most if not all of it from. So good to make sure you’re measuring it correctly.

Yup. I just did a calibration with RODI and realised that’s the reason. I’m annoyed. About to do a water change

fachatga · May 10, 2021

Great. Good call @NeonRabbit221B

NeonRabbit221B · May 10, 2021

FRANK48 said:
Yup. I just did a calibration with RODI and realised that’s the reason. I’m annoyed. About to do a water change

Rodi shouldn’t be used to calibrate. You should use a solution around where you want the tank (1.0265 is a common calibration standard) instead of doing a water change just top off with salt water. I would only water change if you are really really low but right now you don’t actually know how off you are.

FRANK48 · May 10, 2021

NeonRabbit221B said:
Rodi shouldn’t be used to calibrate. You should use a solution around where you want the tank (1.0265 is a common calibration standard) instead of doing a water change just top off with salt water. I would only water change if you are really really low but right now you don’t actually know how off you are.

Alrighty I’ll do that, but I did water change because my salinity was pretty low

ReefRusty · May 11, 2021

What was your salinity before a water change? Hopefully it wasn't a big increase.. always adjust things over a period of time. Even if its over a few days. Sudden increases could have a mass inpact on the tank life

FRANK48 · May 11, 2021

ReefRusty said:
What was your salinity before a water change? Hopefully it wasn't a big increase.. always adjust things over a period of time. Even if its over a few days. Sudden increases could have a mass inpact on the tank life

I think it was something like 1.020 but everything looks fine right now

FRANK48 · May 11, 2021

ReefRusty said:
What was your salinity before a water change? Hopefully it wasn't a big increase.. always adjust things over a period of time. Even if its over a few days. Sudden increases could have a mass inpact on the tank should I still dose

NeonRabbit221B said:
Rodi shouldn’t be used to calibrate. You should use a solution around where you want the tank (1.0265 is a common calibration standard) instead of doing a water change just top off with salt water. I would only water change if you are really really low but right now you don’t actually know how off you are.

ReefRusty said:
What was your salinity before a water change? Hopefully it wasn't a big increase.. always adjust things over a period of time. Even if its over a few days. Sudden increases could have a mass inpact on the tank life

Should I still dose magnesium?

ss30 · May 11, 2021

FRANK48 said:
So I did a yet and my magnesium is 1110. Is this bad or good, I’m want to start getting corals and also try to eventually grow coralline algae

What is your salinity now and what salt are you using?

ReefRusty · May 11, 2021

FRANK48 said:
I think it was something like 1.020 but everything looks fine right now

What has your salinity been increased to now? Hopefully it fixes your magnesium issue, you will probably see an increase in cal and alkalinity as well die to using more Salt..

Magnesium would be the least consumed of the 3 but alkalinity and calcium work with and against each other. Depending of what corals you have, generally at the start every water change is enough to keep levels at a good point.

But when you start adding life and corals they will start to be consumed and will need to dose every day to keep it at a good level without large swings in your parameters.

Randy Holmes-Farley · May 11, 2021

FRANK48 said:
Would this help magnesium?

Yes. Every element in seawater is raised or lowered as you raise or lower the salinity.

If your salinity is very low, that could explain very low magnesium.

Randy Holmes-Farley · May 11, 2021

FRANK48 said:
Should I still dose magnesium?

As I stated before: NO.

If it is low salinity or test error, you will cause a problem by dosing, not solve one.

Randy Holmes-Farley · May 11, 2021

FRANK48 said:
I think it was something like 1.020 but everything looks fine right now

That very low specific gravity is the problem.

If you boost it to natural seawater levels (sg = 1.0264), magnesium will rise to actually higher than normal seawater levels.