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neverwouldof
03/06/2011, 03:10 PM
Hey Guys,

I just need another set of eye's on this formula they give for a concentrated Mg dosing Solution. I have a 75 Gallon Total Volume Reef tank with a lot of SPS. Just bought the tank complete and Cal and Mg were low. I have a bubble Magus that will dose every hour but I need reassurance on the level and ML to dose to increase about 40-50ppm a day. I'm going to make 32oz of Solution with 16 teaspoons Magnesion-P. So 75 ml of solution will raise my tank 6.0 ppm. So I need to add 525 ml of that solution per day to raise around 40-42ppm per day? Would that be correct or am I missing something? Seems like a lot... Thoughts?

Next week the BRS stuff will get here and i'll switch to 2 part plus Magnesium dosing....

From Brightwell Instructions: Create a stock solution by dissolving 20 grams (~4 teaspoons) of Magnesion-P in 8-fl. oz. of fresh water (preferably purified); each ml of the solution will increase magnesium concentration (”[Mg2+]”) in 1 US-gallon (3.785 L) of water by 6.0 ppm. [Reference: Each g of Magnesion-P will increase the [Mg2+] in 1 US-gallon (3.785 L) of water by 114.4 ppm.] If initial [Mg2+] in the aquarium is below 1,288 ppm, add stock sol’n at maximum rate of 10 ml per 20 US-gallons daily until desired [Mg2+] is attained, then dose daily or weekly as needed.

neverwouldof
03/06/2011, 06:51 PM
I'm guessing there is no one here that made it out of high school either? Damn those public schools!

NewSchool04
03/06/2011, 11:57 PM
Try this reef chemistry calculator, it should do all the work for you courtesy of jdieck.

http://reef.diesyst.com/flashcalc/flashcalc.html

Jimmy54
03/07/2011, 04:39 AM
Please don't raise the Mg concentration more than 20 ppm per day.
You won't kill anything when it's 30 ppm per day but try to keep at 20 ppm, 10ppm in the morning and 10 ppm around 7 or 8 pm.
If both calcium and magnesium are low, perhaps you better do a 25% w/c first.

It's always "alot" you need for raising magnesium, has somthing to do with the molar mass.
But your calculations are fine.

bertoni
03/07/2011, 02:12 PM
The usual recommended limit for magnesium dosing is 100 ppm per day. Targeting 50 ppm for the first dose probably is good, though, since getting the water volume requires some guessing.

seapug
03/07/2011, 02:20 PM
If both Magnesium and Calcium are low, you might consider just using BW Reef Code A. It contains both calcium and magnesium in the proper proportions so you don't end up with see-sawing Calcium/Mag/Alk from trying to correct each separately. While it can take a little longer to reach the target levels, I've found correcting both simultaneously (while monitoring your Alkalinity) is a much better long term course of action.

Jimmy54
03/08/2011, 12:30 PM
The usual recommended limit for magnesium dosing is 100 ppm per day. Targeting 50 ppm for the first dose probably is good, though, since getting the water volume requires some guessing.

Not sure if ppm is the same as mg/l
Usually the recommended max raise/day for alk is 1dkh - for calcium10 mg/l and for magnesium 20 mg/l - on this side of the globe :)
Maybe your calculations are ppm/gallon, mine is mg/l, that could explain the difference ;)

bertoni
03/08/2011, 07:08 PM
mg/L and ppm are the same, for hobbyist purposes. There's about a 2% difference:

http://reefkeeping.com/issues/2005-08/rhf/index.php#ppm