Mixing magnesium

[Lee belk]

Hi I’m new to keeping coral and very interested in keeping different types in my tank I’m wanting to know how to mix magnesium’s together like
Mag chloride
Mag sulphate to a ratio that can be used very simply when I have test my mag levels how much water i need to both products weight and if someone could tell me why you can’t just use one or the other for long term because to what I have been reading it causes problems as time passes I’ve tried to make sense of it all but it’s a bit overwhelming to take so much in at one time would using one over the other cause algae I’ve read this somewhere but I haven’t got a clue what to believe if some one could help me out it would be appreciated and the knowledge gained would be applied to other people seeking help

 

[DanyL]

The reason why you’d want to use a mix of both is due to ionic balance. There are people over here that would likely be able to explain it better than I do, and I’ll leave it for them.

As for a recipe, this is what I’ve been using for over a decade now:
Magnesium Chloride Hexahydrate: 300g
Magnesium Sulphate Heptahydrate: 180g

These are the amounts to make a 1 liter solution, which would total at around 545ppm per 100L, or 5ml per 100L for an increase of 9ppm.

 

[Lee belk]

The reason why you’d want to use a mix of both is due to ionic balance. There are people over here that would likely be able to explain it better than I do, and I’ll leave it for them.

As for a recipe, this is what I’ve been using for over a decade now:
Magnesium Chloride Hexahydrate: 300g
Magnesium Sulphate Heptahydrate: 180g

These are the amounts to make a 1 liter solution, which would total at around 545ppm per 100L, or 5ml per 100L for an increase of 9ppm

I understand what u mean now so mixing both stops any imbalances of mag so if I was to buy two 10kg bags of each product at 100 percent raw form I could just mix them at a smaller ratio to achieve a ppm of nearly 10 ppm and just use that year round to keep my mag levels stable without worrying about it getting out of ionic balance I was worried about this just using one type of mag could I mix this solution up in a tub and dose it accordingly with a doser without it settling and dosing too much from not been mixed regularly

 

[Nano_Man]

Epsom pure salts raises mag

 

[DanyL]

I understand what u mean now so mixing both stops any imbalances of mag so if I was to buy two 10kg bags of each product at 100 percent raw form I could just mix them at a smaller ratio to achieve a ppm of nearly 10 ppm and just use that year round to keep my mag levels stable without worrying about it getting out of ionic balance I was worried about this just using one type of mag could I mix this solution up in a tub and dose it accordingly with a doser without it settling and dosing too much from not been mixed regularly

Well, the Magnesium Sulfate originated from the classic Balling method in order to replenish Sulfate.
But it isn’t the only salt you’d need to add back to rebalance the ratios created by the additional Sodium Chloride in the water.
For the rest of the salts the Balling method used a “Sodoium Chloride free salt” which if I remember correctly contained 72 elements and basically lacked the sodium chloride portion found in NSW to compensate on its addition from the Alk, Ca and Mag supplements.

Not many use this method, even those that use the Mag mix I posted above like me.
Instead, I found that using it together with Red Sea Traces and using NSW for weekly water changes results in perfect ICP tests most of the time.

As for the amounts - 10kg each would likely be a lot more than you need unless you already have a large and well established reef tank.
I would get 2kg of Magnesium Chloride and 1kg of Magnesium Sulfate and it’ll probably last you for a good period of time, especially if you’re just starting out.

 

[Lee belk]

I see mate I was saying if I buy 10kg of each product of mag I could just weigh an amount needed of each to make the right amount of mag for what ever the mag needed to be replenished back to and save the rest for the next time I needed to make more up would it be ok to get a rough estimate on how much my tank uses a day by testing mag every week then make a solution up that’s needed to be dosed by my doser with out it settling at the bottom of the container or would it just stay suspended in the water I’m not sure if it would settle and dose to water leaving the mag at the bottom

 

[Randy Holmes-Farley]

I see mate I was saying if I buy 10kg of each product of mag I could just weigh an amount needed of each to make the right amount of mag for what ever the mag needed to be replenished back to and save the rest for the next time I needed to make more up would it be ok to get a rough estimate on how much my tank uses a day by testing mag every week then make a solution up that’s needed to be dosed by my doser with out it settling at the bottom of the container or would it just stay suspended in the water I’m not sure if it would settle and dose to water leaving the mag at the bottom

Properly made mag dosing solutions are fully dissolved and cannot settle. The point being made is you will use far, far more of magnesium chloride than magnesium sulfate.

 

[DanyL]

I see mate I was saying if I buy 10kg of each product of mag I could just weigh an amount needed of each to make the right amount of mag for what ever the mag needed to be replenished back to and save the rest for the next time I needed to make more up would it be ok to get a rough estimate on how much my tank uses a day by testing mag every week then make a solution up that’s needed to be dosed by my doser with out it settling at the bottom of the container or would it just stay suspended in the water I’m not sure if it would settle and dose to water leaving the mag at the bottom

I understood what you meant by getting 10kg of each - what I was saying is that if you don’t have a lot of corals in a big tank - that amount might last you for years. And you’ll also end up with too much Magnesium Sulfate to Magnesium Chloride.

As for settling - if it’s properly concentrated that it would fully dissolve and would not settle.

You don’t have to make enough just for a week, but you could go with a much higher volume that would last you for a month, 2 or more - it’ll be more convenient for you.

As for dosing amounts - you could test Mag and dose it accordingly, or you could dose it in ratio to Ca like Randy suggested in his RMM article.

 

[Lee belk]

Ok I was just making sure I wasn’t confusing anyone and I didn’t get anything wrong through misunderstanding it that’s what I will do I’ll just go along with dosing it in a large container thank you

 

[Randy Holmes-Farley]

Ok I was just making sure I wasn’t confusing anyone and I didn’t get anything wrong through misunderstanding it that’s what I will do I’ll just go along with dosing it in a large container thank you

Here’s the diy recipe, assuming you are not using calcium chloride for calcium;

Do-It-Yourself Magnesium Supplements for the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com

And here’s a even better plan for a new tank: ignore magnesium entirely

Just say NO to magnesium testing: RMM is born

OK, this thread has been many years in the making, and I'm posting it here since folks in the chem forum are probably already tired of all the threads relating to problematic magnesium testing. I'm going to propose a method, let's call it the Randy Magnesium Method, or RMM for short. All good...

www.reef2reef.com

 

[Lee belk]

I’m assuming that using cal chloride is bad because using mag chloride causes too much chloride?

 

[Lee belk]

And would using lime water be fine since it’s calcium hydroxide

 

[Randy Holmes-Farley]

I’m assuming that using cal chloride is bad because using mag chloride causes too much chloride?

It's not bad, it just alters how much chloride form of mag you want relative to sulfate.

 

[Randy Holmes-Farley]

And would using lime water be fine since it’s calcium hydroxide

Limewater is a fine additive. i used it for 20 years.

 

[Lee belk]

I understand thanks again I’ll give it a go sure to run into some problems but we all learn from mistakes but with the advice I’ve been given surely they won’t be too big

 

[Lee belk]

The reason why you’d want to use a mix of both is due to ionic balance. There are people over here that would likely be able to explain it better than I do, and I’ll leave it for them.

As for a recipe, this is what I’ve been using for over a decade now:
Magnesium Chloride Hexahydrate: 300g
Magnesium Sulphate Heptahydrate: 180g

These are the amounts to make a 1 liter solution, which would total at around 545ppm per 100L, or 5ml per 100L for an increase of 9ppm.

When making this solution would you be best using a whole liter of water then add both magnesium products at the same time or individually or would it be best to take out half of a liter add one magnesium shake it then add the half liter of water and then add the other and shake again maybe I’m over thinking it because that and wouldn’t the solution be more then a liter in total after adding both products

 

[DanyL]

I take a measuring cup (1 liter or more in your case), put it on scale, hit “tare” then measure 300g of Magnesium Chloride, then hit “tare” again and measure 180g of Magnesium Sulfate.

And finally, I fill the measuring cup with RODI to the 1 liter mark and mix it well with a wooden spoon for a few minutes until it clears up.

 

[Randy Holmes-Farley]

When making this solution would you be best using a whole liter of water then add both magnesium products at the same time or individually or would it be best to take out half of a liter add one magnesium shake it then add the half liter of water and then add the other and shake again maybe I’m over thinking it because that and wouldn’t the solution be more then a liter in total after adding both products

The volume effect is small, but the recipe says to a final volume, so yes, don’t add all the water at first.

 

[Lee belk]

The volume effect is small, but the recipe says to a final volume, so yes, don’t add all the water at first.

Hi Randy if I was to follow the your 2part mixture of mag chloride and mag sulphate would it be right selecting the Randys recipe 1 and 2 versions a and b on the
Reef Chemistry Calculator ©
By: JDieck I usually use this calculator because I’m not such a bright spark and could you tell me the weight in grams instead of how many cups because we don’t really use the cup method here in the uk and am I right in thinking a liter of water here is the same as the United States 1000ml

 

[Randy Holmes-Farley]

Hi Randy if I was to follow the your 2part mixture of mag chloride and mag sulphate would it be right selecting the Randys recipe 1 and 2 versions a and b on the
Reef Chemistry Calculator ©
By: JDieck I usually use this calculator because I’m not such a bright spark and could you tell me the weight in grams instead of how many cups because we don’t really use the cup method here in the uk and am I right in thinking a liter of water here is the same as the United States 1000ml

Yes