Can i dose AF Mag (solid) directly?

[LucentFish]

Hi,

iv been trying to find an answer to see if it is ok to manually dose the AF MAG supplement directly to tank, in the sump, instead of into RODI then adding. Or in a bucket of tank water/new salt water to raise the level? Otherwise wouldnt the RODI/MAG lower the salinity? i would be looking to raise the level by 100 - 150 ppm over a couple weeks.

Mag level is lower than i would like. MG 1200-1250, AF test. Ca 440, DKH 9, salinity is a bit high, 1.027 on calibrated refractometer.

 

[blaxsun]

The solid needs to be premixed with RO so it can dissolve properly, so no - I wouldn't (I use Nyos magnesium powder mixed with RO - essentially the same).

 

[Randy Holmes-Farley Verified Community Expert]

There's no reason to dose magnesium solids. It is very soluble and wont' take much Ro/DI.

The concern is an undissolved particle landing on a delicate organism.

 

[LucentFish]

Ok, so will 100% mix with RODI. From there, the AF instructions are to dissolve 10g per 1000ml to get 1ppm increase per 100L. So will it dissolve/mix ok to do more grams per 1000ml RODI? The BRS calc says i would need about 500g total. so the idea would be ~ 150g mag to 1000ml x3. Or do i need to dilute it more?

edit: basically is there a max/min concentration of Magnesium that can go into the 1000ml of RODI.

 

[Randy Holmes-Farley Verified Community Expert]

You can make most magnesium solutions as concentrated as you want. You should be able to dissolve at least 300 g/L.

 

[LucentFish]

You can make most magnesium solutions as concentrated as you want. You should be able to dissolve at least 300 g/L.

Amazing thank you, for whatever reason I could not find that on any of the directions/mixing videos. Just the baseline per 1ppm increase per 1000ml.