magnesium

T

Tag

Now that my cyno, and chaeto problems have been resolved its time to take care of my low magnesium. Got a couple of questions:

Twopartsolutions has - High Purity Aquarium Magnesium Chloride (Mag Flake), and High Purity Magnesium Sulfate (epsom Salt). Do I need to use both ingredients or just one. What is the recommended solution?

and is there anywhere locally that I can buy this stuff?



Thanks to all that helped me with the cyno, and chaeto. advice was spot-on
Tag
 
Epsom salt you can buy locally. I bought a large container at Walgreens or CVS for $1 or so.

Take 1 gallon of RO/DI, pour it in a bucket. Add 7.25 cups of Mag Flake an 3/4 cup of Epsom salt, and mix well. I drop a clean powerhead in the mixture and let it mix for 30 minutes or so. Using 1/2 tubing, I siphon it out of the bucket into some clean 2-liter bottles.

To know how much to dose, use this calculator. You are using Randy's Recipe #2 for Magnesium, which it will ask for.
http://jdieck1.home.comcast.net/~jdieck1/chemcalc.html
 
keep an eye on your salinity as you use this method. I found that mine would increase pretty dramatically..HTH
 
@Reefer madness wrote:
keep an eye on your salinity as you use this method. I found that mine would increase pretty dramatically..HTH said:
Thanks for the warning........ :wink:
Click to expand...
 
That is the one from a year ago Rick.

http://reefkeeping.com/issues/2006-07/rhf/index.php

From the article:

 
Also, if you're using RHF's two-part dosing, he mentions sticking with the Mg recipe provided there- more MgSO4 is needed to offset the chloride associated with that recipe.
 
@Ashlar wrote:
Also said:
Why did he greatly lower the epson salts which the magnesium sulphate versus the Mag Flake which is the magnesium chloride? It used to be like 5 cups Magflake to 3 cups epson salts.

It sounds like he wanted a lot more chloride in the mix versus the sulphate.
Click to expand...
 
I thought the recipe was 60% 40% of the two. That does seem like a very low level of epsom salt than I remember. Let me look today and see.
 
Bingo, Rick. The two-part recipe is already heavy in chloride, so the mag supplement with that is heavier on the sulfate. This recipe for mg supplementation is more for those who use water changes, commercial two part additives, or calcium reactors to supplement.
 
I found this in the middle of the article:

[Note that these sulfate rise values are lower, for a given calcium and alkalinity dosage rate, in this model than I have shown previously for my DIY two-part additive recipe. The reason for this difference is that in that case, additional magnesium sulfate is required to offset the rise in sodium and chloride that comes along with the calcium chloride and baking soda. Such differences are unimportant for typical aquarists to understand, but this explanation is provided for those who noted and were confused by the difference.]

I think this says what Ashlar ( Scott ) said. If you are using his DIY recipe, you can stay with the approx 60/40 ratio. If not but are just using the DIY for magnesium, you can avoid a sulfate build up by using a 10/1 ratio.

Anyone differ with my reading?
 
Lol, RHF doesn't make it easy to understand, sometimes. I agree with Gary's interpretation- if using RHF two-part, use the Mg supplement defined there. Otherwise, use this other one.
 
Since I started dosing in this method, my Magnesium has stayed very stable. I've not quite got it nailed down to 'X ml per week' yet, but it has been very easy to keep Mg over 1400 in my tank with recipe (7.25 + .75)
 
In the past, I would dose every couple of months. I just used a bunch of scoops of Mag Flake, filling a 1/2g pitcher half way with media. I'd add RO/DI water, mix it up well and drip that into my system over the next few hours. Which of course brought it way up, but it wasn't measured and not a good method.

About 3 months ago, I decided to mix it up correctly (as posted here), and then used Jdieck's calculator to determine what I needed to add. 330g of water volume, RHF Recipe #2 for Magnesium, current level of Mg input into the calculator, and it would state how much to add. The first time, I had to dose 1356ml and thought that sounded high. A 2-liter bottle holds 2000ml, so it was something like 68% of a bottle. (These numbers are from memory, and could be off mathematically) I've been dosing about every 2 to 3 weeks with the correct amount.

Using that calculator, you can figure out exactly how much to add. And if I do this every week for a couple of months, I could lock in a number of how much to dose each weekend. If I have to add 200ml weekly and that keeps the number very stable, that's a good thing and one less parameter to worry about.

Rick had ordered a bunch of bags of Mag Flake in a Group Buy, and I bought a full bag from him.
 
I just got this reply from Randy today.

Marc:

There is no reason to think the MAG flake may have changed. Neither I nor they will guarantee that no changes have been made (and that was the point of the warning), but there have not been any known change. :)

http://reefcentral.com/forums/showthread.php?s=&postid=11389172#post11389172
 
Other than affecting salinity and not adding the Mg too fast are there other concearns when dosing Mg?

I recognize the relationship between Ca and Alk. And that Mg allows more saturation of Ca in the water colum. But will adding Mg change the results of a Ca or dkh test?

I'm guessing the answer to this question is no... but I've never added Mg to a system before and I want to be sure.

I'll be using Reef Crystals for my new tank and Mg appears to test around 1110 on a fresh batch. For those of you with low Mg do you add it to your makeup water or do you just dose the entire tank on a regular basis? If you add it to your makeup water do you add it before or after the salt? I was thinking of just adding the Mg to the Ro/DI water and mixing in the salt after it disolved.

thanks,
Ben
 
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