Dosing Red Sea Foundation C Magnesium

[Paulm7373]

I have a 50g well established reef tank with mostly LPS corals. I just tested my Mg level using the Red Sea Magnesium test kit and it was 1200. The leaflet suggest optimum level for LPS is 1310. I received my Red Sea Foundation C powder to boost Mg levels and the dosing instructions aren't very clear. Can anyone suggest a good weekly or daily dosing plan to gradually increase my Mg to where it should be, which basically means increasing it by an extra 100 or so?




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[jeffaquarius]

The powder magnesium has to be mixed first in ro/di water then add that mixture to your tank. The instruction should tell you the ratio of powder per volume of water. Adding mag is not that critical compared to other trace elements. Just keep in mind that mag, alk and calcium have some inverse effect with one another. I believe the max for mag is 10 ml/20 gal per day. Which means you can add 25 ml on your 50 gal each day until you reach your target. Roughly it may raise about 20 points daily.

 

[Paulm7373]

The only ratio of powder per volume of water I could find based on my current Mg level of 1200 is 82 grams per 100L (25g) meaning I would need 164 grams for 50g in order to achieve an optimum Mg level of 1310. So if I gradually wanted to increase it daily over the space of a week, would I need to add about 23 grams daily? If so, how much RO water do I add the 23 grams of powder in? Do I then add it into my sump?




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[Ingy]

Do you have an ATO? Dissolving the powder in rodi then adding it to your ATO reservoir might work. Just watch for any scaling or precipitate after the first cycle. It won't hurt anything the first try, but if it's evident all the mag is not getting into the tank you will have to divide the dose and add it every day or 2.
For daily dosing option, you need to divide the dose you calculated by the max daily addition (20 ppm I believe).
So your 110 point addition should be spaced over 5-6 days. That means divide your 164 gm by 5-6 and add it daily.
Once you've brought it up you need to reduce your dosing until it stabilizes at your target level.
As he mentioned raising the mag will have an effect on your calc and all levels depending on your coral stocking levels. It may raise them both in a lightly stocked tank or it may lower them both in a heavily stocked tank ( there are biologic and non-biologic factors that compete here).


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