Dosing Mg

[Aldente P.]

My Mg in the tank was 720, the new water was 820. Did the water change. Then added the maximum dosage of Mg, tested this morning and it was only 750. Is this normal? If so its going to take alot to get me caught up! :shock: I did have filter media in the fuge, could it have filtered all the supplement out of the water? TIA

 

[kwl1763]

Ya it takes a ton! The reason being that even high purity is only like 8% I think or something like that Mg. It takes tons to raise. If the tank is not huge I would just start making new saltwater at 1500 and change like 20% frequently until it's raised. You could probably use more then the "max dose" though You don't want to do more then about 50-100 per day though.

 

[Rick]

It takes a lot of a magnesium to raise the levels. Just to give you an idea, on my 215 it took about 8- 10lbs of pure magnesium salts to raise it from a 1000 to 1350/

 

[bimmerzs]

If you can get some Mag flake or similar then the DIY magnesuium recipe(with epsom salt) seems to do a better job of raising mag levels. Make sure not to increase over 100ppm a day so you don't stress your coral's.

Cheers!

 

[melev]

The 'new' recipe is 7.25 cups of Mag Flake and 3/4 cup Epsom Salt in 1g of RO/DI water. I just finished mixing up a batch.

Hey Rick, you think you might want to do one more group buy for Mag Flake before all the old stuff is off the shelves?

 

[Ashlar]

'New' recipe? Got a link?

 

[Rick]

@Marc wrote:

? Old stuff?

 

[GraviT]

@Marc wrote:

I know there are concerns about the 2007 batches of Dow Flake being excessively high in borate, what's up with Mag?

 

[Wes]

what is ideal?

id be in for a gb

 

[Aldente P.]

Thanks for all the replys! Rick after getting to the level you wanted did it take alot to keep it there. Or is getting there the big problem? Not sure what mag flake is but if its a cheaper salution to my problem then i may be interested in a GB.

 

[melev]

@Ashlar wrote:

Well, I read it. Let me find it for you.
http://reefkeeping.com/issues/2006-07/rhf/index.php

It isn't a new article, but the recipe had changed from a former one.

 

[melev]

@Rick wrote:

? Old stuff?"]

The company that makes Mag Flake has not only changed the recipe of the product, but contacted RHF to inform him that it was not Aquarium Safe. There has been some discussion about this, along with conjectures about how much of an issue that is. The bottom line is that there is enough of the stuff out there on the shelves that are from older batches that I'm leaning on the idea of getting an extra bag before I'm forced to find a different option.

Using that exact recipe (quoted above) today, I mixed up 1 gallon of the stuff, and stored it in 2-liter bottles for when I need to dose. How are you dosing Rick? Do you mix up only enough for a single dose, or are you making up a solution as well? How often do you add it? Only when the numbers drop, or on a regular basis?

I tested my tank today, and it was 1400ppm. Which sparked a bit of a discussion on RC, because I get this weird delayed reaction in Magnesium test results.
http://reefcentral.com/forums/showthread.php?s=&postid=10650254#post10650254

 

[Ashlar]

Hrmm.. from the article..

@RHF wrote:

Sounds like he's saying that if you're doing his 2 part, stick with that recipe, no?

Also, I got the bulk mg from twopartsolution.com that says "This is a special High Purity Magnesium Chloride that is specifically made for the aquarium industry. This product does not contain any phosphates or ammonia." and they recommend mixing it up at the same ratio as RHF's recipe (5 cups / 3 cups epsom).

 

[Rick]

Marc I dose it when I see it drop. I have not had to dose as much as I used to , now that I use ReefCrystals. Which is the main reason I switched to that from Instant Ocean. I still have a bucket of magflake left.

 

[ToddLaCo]

The best way to dose for Mag or any supplement would be to get your level where you want it, then don't add any for about seven days or so. At the end of seven days test your levels and divide by seven. Voila, you now know how much your system depletes that compound every day.

For example, I did as I stated above and my system uses about 5.5 ppm of magnesium every day. I am adding 50-60 ML of Kent Tech-M Mag every day and it keeps my levels right where I want them at about 1400 ppm.

 

[Rick]

@ToddLaCo wrote:

Great idea. Do you consider water changes and what salt are you using?

 

[ToddLaCo]

Unfortunately I Have not been changing my water as regularly as I should since I only had 3 small fish and no coral in the tank until recently. Now that I have added more fish and some coral I will be starting to do about 35 gallon water changes weekly. I will have to keep an eye on my levels and refigure my supplementation when everything levels out with water changes, and I will also ensure my water change water is at the appropriate levels so I am not working against my supplementation. I am currently using Reef Crystals and I think it falls a little short on mag.

 

[ToddLaCo]

Well, I just completed a water change and now that I have a lot more life in my tank I am going to stay on the weekly 35 gallon routine.

I tested my fresh salt water (Reef Crystals) before adding to the tank and the Mag was only 1000 ppm. I added 25 ml of Kent Tech-M to 35 gallons and all is good.

 

[melev]

I mixed up a new batch of Red Sea Coral Pro salt and tested it. Here are the test results:

pH 8.28
salinity 1.026
temp 80
Alk 8.6 dKH
Mg 1230
Ca 425
PO4 0
NO3 0

Magnesium is higher in this batch than Todd's. What about yours, Rick?

 

[Rick]

Last time I tested Reef Crystals this is what I got.
Calcium 380-400ppm
Magnesium 1240ppm
Strontium 4-10ppm (hard test)
Iodide .03ppm
Alkalinity 9.6 dkh