Which Magnesium to use

jsker · Sep 11, 2015

I am currently using Seachem reef advantage magnesium. Would you switch to bulk reef supply Magnesium? Which Bulk reef supply Magnesium would you suggest I use and why? let keep it simple.

Randy Holmes-Farley · Sep 11, 2015

What will you be using it for and how are you dosing calcium and alkalinty?

(the answer matters)

twilliard · Sep 11, 2015

I agree with randys direction
When I have to do adjustments I use seachem magnesium
When I tackle bryopsis I use techM

jsker · Sep 11, 2015

Randy Holmes-Farley said:
What will you be using it for and how are you dosing calcium and alkalinty?

(the answer matters)

I am using the magnesium to maintain magnesium and also raise the level. My tank is now been setup for 8 months.
Today I am setting at
mg 1350
Ca 470
Alk 7.7
PH 7.7
I have been dosing with my ATO and added 2 tbls of kalwasser to the ATO today.
I am going to do the research on a dosing systems later tonight and tomorrow to see my options for setting one up.

twilliard said:
I agree with randys direction
When I have to do adjustments I use seachem magnesium
When I tackle bryopsis I use techM

I think I just might stick with seachem. I have had good success with seachem magnesium in the past and I was looking around for a deal and was think of switching product if the bulk reef product was as good.

Randy Holmes-Farley · Sep 12, 2015

OK, if you are using limewater for calcium and alkalinity, I'd use either magnesium chloride alone or a mix of 10 parts of magnesium chloride to 1 part magnesium sulfate (Epsom salt from a drug store).

You can get the magneisum chloride from BRS or Dr Foster and Smith (or other places).

jsker · Sep 12, 2015

Randy Holmes-Farley said:
OK, if you are using limewater for calcium and alkalinity, I'd use either magnesium chloride alone or a mix of 10 parts of magnesium chloride to 1 part magnesium sulfate (Epsom salt from a drug store).

You can get the magneisum chloride from BRS or Dr Foster and Smith (or other places).

Thank you very much Randy for the feed back.

Randy Holmes-Farley · Sep 12, 2015

You're welcome.

Happy Reefing.

jsker · Oct 13, 2015

Good Evening @Randy Holmes-Farley it me again

I received my Magnesium Chloride from Bulk Reef supply. I am going to mix the 2 part according your recipe. is there a shelve life on the liquid, or should I mix it dry and dilute as a go?

Vivid Aquariums · Oct 13, 2015

We run our store on Seachem Reef Advantage Magnesium. We have also used Brightwell Magnesion in the past. You can't go wrong with either one.

Dave

Randy Holmes-Farley · Oct 13, 2015

jsker said:
Good Evening @Randy Holmes-Farley it me again I received my Magnesium Chloride from Bulk Reef supply. I am going to mix the 2 part according your recipe. is there a shelve life on the liquid, or should I mix it dry and dilute as a go?

No shelf life. It lasts forever, if you prevent evaporation.

Randy Holmes-Farley · Oct 13, 2015

Vivid Aquariums said:
We run our store on Seachem Reef Advantage Magnesium. We have also used Brightwell Magnesion in the past. You can't go wrong with either one.

Dave

I agree that those are likely both fine products, although Brightwell Magnesion P has some incorrect information in it's description.

notably here:

http://brightwellaquatics.com/products/magnesionpt.php

it claims that it is

Guaranteed Analysis
Magnesium (min) 43% (430,000 ppm)

which is utterly untrue. They have had that incorrect info for many years, which leads me to worry that may not really understand their own product. It cannot be more than about 25.3% magnesium.

jsker · Oct 13, 2015

Vivid Aquariums said:
We run our store on Seachem Reef Advantage Magnesium. We have also used Brightwell Magnesion in the past. You can't go wrong with either one.

Dave

I am currently using Seachem Reef Advantage, the cost difference going the way I'm am going now is a great deal.

jsker · Oct 13, 2015

Randy Holmes-Farley said:
No shelf life. It lasts forever, if you prevent evaporation.

Thank you again

Randy Holmes-Farley · Oct 13, 2015

FWIW, it is not just the guaranteed analysis that is so far off, but the whole Brightwell description of how much it raises magnesium per gram added. Really poor product understanding.

Randy Holmes-Farley · Oct 13, 2015

jsker said:
Thank you again

You're welcome

Happy Reefing.

sawdonkey · Oct 13, 2015

Randy Holmes-Farley said:
OK, if you are using limewater for calcium and alkalinity, I'd use either magnesium chloride alone or a mix of 10 parts of magnesium chloride to 1 part magnesium sulfate (Epsom salt from a drug store).

You can get the magneisum chloride from BRS or Dr Foster and Smith (or other places).

Do you care to elaborate on why you make this suggestion? I use kalk and I've been using the BRS premixed chloride/sulfate? Is this not appropriate, and why? Thanks.

biom · Oct 13, 2015

Randy Holmes-Farley said:
Guaranteed Analysis
Magnesium (min) 43% (430,000 ppm)

which is utterly untrue. They have had that incorrect info for many years, which leads me to worry that may not really understand their own product. It cannot be more than about 25.3% magnesium.

I think they simply sum mass percent of Mg in MgCl2 and MgSO4 which will give you about 45%... speechless

biom · Oct 13, 2015

sawdonkey said:
Do you care to elaborate on why you make this suggestion? I use kalk and I've been using the BRS premixed chloride/sulfate? Is this not appropriate, and why? Thanks.

Because when using kalk as calcium/alkalinity supplement you are not changing ion balance, that's why you don't need extra sulfates as it will be the case if using two part. You'll need only small amount of sulfates to compensate chlorides coming from MgCl2, but they are really small amount and could be ignored if there are water changes in place. So I suppose BRS premixed Mg is designated for two part dosing and will add extra sulfates to your tank you don't needed.
Upps I did it again (answered instead of Randy, and he will punish me finally :0)

Randy Holmes-Farley · Oct 14, 2015

sawdonkey said:
Do you care to elaborate on why you make this suggestion? I use kalk and I've been using the BRS premixed chloride/sulfate? Is this not appropriate, and why? Thanks.

It is probably not optimal. The 5:3 ratio (which BRS sells for use with the two part) is used when you are using calcium chloride for calcium. That adds a lot of chloride. So when you use magnesium along with that (as you should) you need relatively less chloride and more sulfate in the magnesium supplement.

When you use kalk, you are not adding any chloride with that, so you need the magnesium supplement to (optimally) contain the natural seawater ratio of chloride to sulfate, which the roughly 10:1 provides.

In reality, you likely will never see any difference in the tank creatures, but there's no reason to not use the proper ratio of sulfate/chloride for the given application.

I discuss the two different ratios in these articles:

Do-It-Yourself Magnesium Supplements for the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2006-07/rhf/index.php

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2006-02/rhf/index.php