Magnesium > 1500

[Rigoberto]

Hello!

I do not dose magnesium. However, I dose 2 part (BRS) and KW. I do weekly 10% water changes with Instant Ocean.

Magnesium is consistently > 1500. I am guessing this is coming from the IO. I am testing with a Red Sea titration kit.

First, is this an issue at all? i.e. Mg > 1500

Should I consider a different brand of salt? Are there concerns with Mg dwelling in the 1500 range?

Thanks,
R

 

[blaxsun]

No. I've had mine over 1500ppm for months on end with no ill effects (I wouldn't go higher than 1600 though). I might suggest doing another test or one from a different test kit.

 

[dstockwell]

Mine has also been at 1500, I stopped dosing kalk after I over dosed, still no I’ll effects.

 

[Rigoberto]

What salt mix are y’all using.

 

[dstockwell]

Reef Crystals

 

[Sean Clark]

I would test with another kit. Odds are it is not an issue.

 

[Randy Holmes-Farley]

My expectation is that the high magnesium is test error, which is very common.

I'd ignore it.

Perhaps try the kit on some new salt water.

 

[Koty]

How do you check your salinity? Maybe your concentration measurments are off and not the Mg.

 

[JGT]

I use RC and Mg is also consistently1450-1500. So much so that I have stopped testing for it and all the Mg I bought thinking I would need to dose is collecting dust.

 

[Rigoberto]

How do you check your salinity? Maybe your concentration measurments are off and not the Mg.

Good point. I have several methods which all read differently... So, I am not 100% the readings are absolutely correct. The most accurate is the Milwaukee digital refract. It checks with a manual refract. These seem to be pretty close relative to known reference solution.

 

[Rigoberto]

My expectation is that the high magnesium is test error, which is very common.

I'd ignore it.

Perhaps try the kit on some new salt water.

I get similar (actually a little higher) readings with the new salt water. I am testing with Red Sea kit.

Any suggestions for alternative measurement approach?

 

[JoJosReef]

No. I've had mine over 1500ppm for months on end with no ill effects (I wouldn't go higher than 1600 though). I might suggest doing another test or one from a different test kit.

What happens after 1600? I've been in the mid 1600s for about 8 months now. Bad batch of HW salt, I think (ALK mixes low, too, but Ca normal range at ~490). I've checked tank and new saltwater with both Red Sea and Salifert Mg tests, both mid-1600s.

I understand it can be hard on your inverts. Not sure how it affects corals, Nems and your water chemistry in general...

 

[blaxsun]

What happens after 1600? I've been in the mid 1600s for about 8 months now. Bad batch of HW salt, I think (ALK mixes low, too, but Ca normal range at ~490). I've checked tank and new saltwater with both Red Sea and Salifert Mg tests, both mid-1600s.

I understand it can be hard on your inverts. Not sure how it affects corals, Nems and your water chemistry in general...

Assuming the test result is correct - probably nothing good long-term. I'm not really willing to offer my reef up as a sacrificial lamb to find out (the highest mine tested was 1585 and I got it back down below 1500 within a month).

I run my tank @1450ppm (+/-), which while not unusual is typically about 50-100ppm higher than most.

 

[JoJosReef]

Assuming the test result is correct - probably nothing good long-term. I'm not really willing to offer my reef up as a sacrificial lamb to find out (the highest mine tested was 1585 and I got it back down below 1500 within a month).

I run my tank @1450ppm (+/-), which while not unusual is typically about 50-100ppm higher than most.

Think you're right. I have new salt arriving next week (Fritz blue), so will start the process of bringing levels to normal range. Thanks!

 

[Koty]

I use Tropic Marine hydrometer. A pain to use but very reliable. As about 500 cc are required, the water temperature during measurments remaine true.