where is my magnesium going?

kevinsmixed90 · May 26, 2015

after joining this forum and reading about the levels of magnesium other reefers are maintaining, I starting to raise my level from 1260 where it stays to 1380 to see what benefits it may have on my tank. no matter what I try my morning tests always read around 1260. I use the brs. two part solution and a salifert test kit. I have tried turning off my carbon and rowa phos. reactors but it makes no difference. I add slowly throughout the day so as not to spike anything but I don't know where it goes. can anyone shed some light on this? I would be grateful to have this mystery solved. any thoughts on the proper levels for my mixed reef leaning more on the soft, lps. coral side would be great too. thanks,

Downbeach · May 26, 2015

Although your current reading is fine, it takes a lot of Mg supplement to elevate it. Here is a good calculator to determine the dose. You can increase it up to 100ppm per day. Fill in the blanks for your system and select Randy's recipe in the drop down menu.

kevinsmixed90 · May 26, 2015

thanks downbeach for the onfo.

Randy Holmes-Farley · May 26, 2015

It isn't being depleted rapidly, which happens very slowly and is dependent on the rate of calcification rate. The magnesium depletion rate is on the order of 1 ppm per day or less in most tanks. It just takes a lot to boost, as noted. Seawater has a LOT of magnesium in it, and all additives are necessarily quite weak in magnesium concentration.

kevinsmixed90 · May 26, 2015

ok, I'll keep dosing but will increase to 100 ppm per day. thanks Dr. Farley for the info.

Randy Holmes-Farley · May 26, 2015

I would not raise it that fast. I'd limit it to 25 ppm per day max due to the concerns about toxic impurities in magnesium supplements (ammonia, heavy metals, etc.).

There's no hurry as you are unlikely to even notice a difference anyway (aside, perhaps, from coralline growing a bit faster).