Magnesium drop100ppm

[joshq7]

Ok so I know I have read on multiple forums that it is impossible to have a 100 ppm drop of magnesium, but it’s happening
Tested display tank 5 times and getting same results 1260ppm mag. Using salifert
test kit. When I test storage container I get 1350
Using tropic marin reef salt.

Salinity 1.025 DT and water storage tank
Mag 1260 consistently for 4 days.
Cal currently 470
Alk 8.6
Ph 8.1
Nitrate 10-15
Phos. 0.25



Roughly 15-20 smaller frags. Hammers,frog spawn, Duncan,bubble tips, rock flower,fox coral
Most coral doing ok but hammers definitely taking a hit.


Was consistently at 1350 mag since I switched to tropic marin salt about 2 months ago
Have dosed roughly 100ml of sr magnesium
Jumped up mag roughly 30 ppm this morning and dropped back down to 1260 by evening

 

[Garf]

Ok so I know I have read on multiple forums that it is impossible to have a 100 ppm drop of magnesium, but it’s happening
Tested display tank 5 times and getting same results 1260ppm mag. Using salifert
test kit. When I test storage container I get 1350
Using tropic marin reef salt.

Salinity 1.025 DT and water storage tank
Mag 1260 consistently for 4 days.
Cal currently 470
Alk 8.6
Ph 8.1
Nitrate 10-15
Phos. 0.25



Roughly 15-20 smaller frags. Hammers,frog spawn, Duncan,bubble tips, rock flower,fox coral
Most coral doing ok but hammers definitely taking a hit.


Was consistently at 1350 mag since I switched to tropic marin salt about 2 months ago
Have dosed roughly 100ml of sr magnesium
Jumped up mag roughly 30 ppm this morning and dropped back down to 1260 by evening

There's a few points that spring to mind.
Magnesium is notoriously difficult to get an accurate reading with hobby test kits. Also, a slight increase in salinity in your mixing bucket could give elevated readings in your mixing bucket compared to the display (5 % of 1300 is 65ppm mag increase for example, but the salinity increase is hard to pickup on hobby refractometers). Thirdly, the reading you are getting in the display when corrected for salinity at 35ppt is actually near enough your target value.

 

[Nano_Man]

Mag looks ok
Natural sea water is around 1300

 

[gbroadbridge]

Ok so I know I have read on multiple forums that it is impossible to have a 100 ppm drop of magnesium, but it’s happening
Tested display tank 5 times and getting same results 1260ppm mag. Using salifert
test kit. When I test storage container I get 1350
Using tropic marin reef salt.

Salinity 1.025 DT and water storage tank
Mag 1260 consistently for 4 days.
Cal currently 470
Alk 8.6
Ph 8.1
Nitrate 10-15
Phos. 0.25



Roughly 15-20 smaller frags. Hammers,frog spawn, Duncan,bubble tips, rock flower,fox coral
Most coral doing ok but hammers definitely taking a hit.


Was consistently at 1350 mag since I switched to tropic marin salt about 2 months ago
Have dosed roughly 100ml of sr magnesium
Jumped up mag roughly 30 ppm this morning and dropped back down to 1260 by evening

How are you measuring salinity?

Is your storage container temperature the same temperature as your display tank?

The difference you are seeing is probably test error combined with a salinity measurement error which may be compounded by a temperature difference.

In any case the exact number does not matter as nothing in the tank would notice a difference.

 

[Randy Holmes-Farley]

There is no chance magnesium has dropped 100 ppm unless calcium dropped by more than 1000 ppm, except by salinity change. ,

Time for RMM:

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...

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