Raising ALK and Magnesium - just Kalk?

Zero_Cool · Jun 4, 2023

230 gallon system
pH 7.98
SG 1.025
Temp 78
PO4 .03
NO3 .5
Cal 440
Mg 1275 (down from 1320 4 days ago)
ALK 7.4 (down from 7.5 4 days ago)

Auto-water change with Reef Crystals has been off for 5 days. Restarting tonight.

Would like to run ALK at 8.5-8.7 and Mg at 1350-1375.

Will dosing saturated Kalk raise both of these or only the ALK (and pH)?

Do I need to brink ALK up with sodium bicarbonate first and then maintain with Kalk?

If not via Kalk, how do I raise the Mg level?

Thank you

rtparty · Jun 4, 2023

Kalkwasser doesn’t contain magnesium. It will maintain/raise calcium and alkalinity.

If you want to up magnesium, you will need a magnesium supplement

Zero_Cool · Jun 4, 2023

Thank you. Once Mg is where I want it, how do I maintain it there?

homer1475 · Jun 5, 2023

Magnesium, is the one product I rarely have to add. It is extremely abundant in sea water. If you do normal water changes, you probably never have to add magnesium.

If you do need to add mag, magnesium chloride, and magnesium sulfate are mixed together in RO/DI and added to the tank. I personally use BRS chemicals, as one bag lasts me may years as my salt mix is high in mag.

I see they do make a 1 gallon mix now, so no need to buy the 2 separate chemicals. You just add this bag to 1 gallon of water.

Pharma Magnesium Mix for 2-Part Maintenance

Ultra Pure Magnesium Additive for 2-Part Maintenance in your Reef Tank! Maintaining proper magnesium levels helps achieve the essential balance of calcium and alkalinity in your tank by preventing excess calcium carbonate precipitation. Not all magnesium additives are created equal and the...

www.bulkreefsupply.com