Randy's Magnesium Recipes 1&2 Question - Dry Dosing?

[tbrown]

Randy or anyone: I recently mixed up some Randy's Part A and B Magnesium using Magnesium Sulfate and Magnesium Chloride. I'm limited on storage space and wanted to make sure my math is correct as it's been a while:

8 cups to 1 gallon means 2 Tbs (1/8 cup) to 2 oz (1/4 cup) water for the same strength.

Dosing that 3 oz solution would raise the magnesium in a 10 gallon tank 100 ppm.

SO: dosing 2 Tbs of dry Recipe 1 and 2 (Recipe 3) per 10 gallons of total system gallons of water raises my Magnesium by 100, right?

My system volume minus rocks and sand and equipment is approximately 65 gallons. So dosing 12 Tbs should raise my magnesium by approximately 100 ppm.

I'm not planning on dosing this all in one shot, just wanted to make sure my math is correct.

 

[Randy Holmes-Farley Verified Community Expert]

Randy or anyone: I recently mixed up some Randy's Part A and B Magnesium using Magnesium Sulfate and Magnesium Chloride. I'm limited on storage space and wanted to make sure my math is correct as it's been a while:

8 cups to 1 gallon means 2 Tbs (1/8 cup) to 2 oz (1/4 cup) water for the same strength.

Dosing that 3 oz solution would raise the magnesium in a 10 gallon tank 100 ppm.

SO: dosing 2 Tbs of dry Recipe 1 and 2 (Recipe 3) per 10 gallons of total system gallons of water raises my Magnesium by 100, right?

My system volume minus rocks and sand and equipment is approximately 65 gallons. So dosing 12 Tbs should raise my magnesium by approximately 100 ppm.

I'm not planning on dosing this all in one shot, just wanted to make sure my math is correct.

I didn’t check the math, but you can use a calculator for dry dosing either of the two ingredients here:

https://reef.diesyst.com/chemcalcnew.html
If this is a dry mix from BRS for use with a two part, you can average them and be close enough.

 

[UMALUM]

Please excuse the hi jack but for the sake of not start8ng a new thread @Randy Holmes-Farley would you be so kind as to remind me AGAIN the proper mixing directions and dosage for tm c in conjunction with your 2 part? My apologies I forgot to write it down and this topic for reasons unknown to myself is all over the map when trying to research.

 

[tbrown]

I didn’t check the math, but you can use a calculator for dry dosing either of the two ingredients here:

https://reef.diesyst.com/chemcalcnew.html
If this is a dry mix from BRS for use with a two part, you can average them and be close enough.

It's not. I bought the two different magnesium types and mixed them in the ratio you have just without mixing with a gallon of water.

 

[Randy Holmes-Farley Verified Community Expert]

Please excuse the hi jack but for the sake of not start8ng a new thread @Randy Holmes-Farley would you be so kind as to remind me AGAIN the proper mixing directions and dosage for tm c in conjunction with your 2 part? My apologies I forgot to write it down and this topic for reasons unknown to myself is all over the map when trying to research.

2 volumes of Balling Part C for each one volume of calcium or alk part.

That recipe neither supplements nor depletes magnesium. If you want to supplement magnesium (which I recommend) then I’d add about 5 mL of my normal diy magnesium mix per 100 mL of the alk or calcium part used.

 

[Randy Holmes-Farley Verified Community Expert]

It's not. I bought the two different magnesium types and mixed them in the ratio you have just without mixing with a gallon of water.

Ok, then you can use the calculator for the dry components averages, or the liquid recipe scaled to whatever volume you dissolve them in that is different than 1 gallon.

 

[Miami Reef]

Hello @Randy Holmes-Farley

This is your magnesium recipe:

Dissolve Epsom salts (magnesium sulfate heptahydrate (3 cups) and magnesium chloride hexahydrate (5 cups) in enough purified freshwater to make 1 gallon total volume.

Is it interchangeable? For example, Can I use 7 cups of Magnesium chloride and 1 cup magnesium sulfate? As long as the total cups of magnesium = 8.

Does it work like that?

 

[Randy Holmes-Farley Verified Community Expert]

Hello @Randy Holmes-Farley

This is your magnesium recipe:



Is it interchangeable? For example, Can I use 7 cups of Magnesium chloride and 1 cup magnesium sulfate? As long as the total cups of magnesium = 8.

Does it work like that?

For magnesium concentration that is mostly ok, for chloride sulfate balance, it is not ok.

 

[tbrown]

For magnesium concentration that is mostly ok, for chloride sulfate balance, it is not ok.

I followed the 7 1/4 cup to 3/4 cup recipe from the article:

https://reefkeeping.com/issues/2006-07/rhf/index.php#13

 

[Randy Holmes-Farley Verified Community Expert]

I followed the 7 1/4 cup to 3/4 cup recipe from the article:

https://reefkeeping.com/issues/2006-07/rhf/index.php#13

That is appropriate for stand alone magnesium supplementing, not associated with using a diy two part.

 

[tbrown]

That is appropriate for stand alone magnesium supplementing, not associated with using a diy two part.

Yep, just the magnesium.

 

[tbrown]

One more quick question: I just ran out of magnesium chloride and LiveAquaria is sold out of the stuff I had been using. I found some on Amazon that says "Unscented" and "Pure Magnesium Chloride". Would it be an acceptable replacement?

Link

 

[Randy Holmes-Farley Verified Community Expert]

The purity for our purposes is unknown. It may be ok, or not.

 

[tbrown]

The purity for our purposes is unknown. It may be ok, or not.

That was my fear. It says "Pure" but no purity %.

 

[rishma]

That is appropriate for stand alone magnesium supplementing, not associated with using a diy two part.

I have a container of Pre-Mixed - Makes 1 Gallon of BRS Liquid Magnesium Mix:

7 1/4 c. Magnesium Chloride : 1/2 c. Magnesium Sulfate

I only mixed 500ml and did it by weight a long time ago. I labeled the container saying 180 grams + 500ml, 0.46 ppm/ml in 100L. I cannot remember how I came up with that or if it’s even close. A quick check would greatly be appreciated.

 

[Randy Holmes-Farley Verified Community Expert]

I have a container of Pre-Mixed - Makes 1 Gallon of BRS Liquid Magnesium Mix:

7 1/4 c. Magnesium Chloride : 1/2 c. Magnesium Sulfate

I only mixed 500ml and did it by weight a long time ago. I labeled the container saying 180 grams + 500ml, 0.46 ppm/ml in 100L. I cannot remember how I came up with that or if it’s even close. A quick check would greatly be appreciated.

It's weaker than my normal recipe, which is about 64 ounces/ gallon (1814 g/gallon) = 240 g/500 mL. I wonder if BRS was either selling a weaker than full pack for a gallon (maybe due to bulk density differences or just poor quality control) and you based it off the total weight they sold, or if there was less moisture than normal in the mag chloride they sold and they used less for that reason.

1 ml of my normal recipe in 100 L adds 0.47 ppm per mL.

So yours would seem to add about 0.35 ppm per mL in 100 L, assuming it was magnesium chloride hexahydrate and magnesium sulfate heptahydrate.

 

[rishma]

It's weaker than my normal recipe, which is about 64 ounces/ gallon (1814 g/gallon) = 240 g/500 mL. I wonder if BRS was either selling a weaker than full pack for a gallon (maybe due to bulk density differences or just poor quality control) and you based it off the total weight they sold, or if there was less moisture than normal in the mag chloride they sold and they used less for that reason.

1 ml of my normal recipe in 100 L adds 0.47 ppm per mL.

So yours would seem to add about 0.35 ppm per mL in 100 L, assuming it was magnesium chloride hexahydrate and magnesium sulfate heptahydrate.

You triggered a memory. I weighed the container and multiplied the weight by whatever 500ml/1gallon fraction equals with the correct units. That’s where 180g came from. Where I got the 0.46 ppm/ml I’m not sure but seems to be based on your recipe.

No obvious way to answer the question of what the actual ppm is, which is why I now prefer to diy stuff. I supposed whether it’s 0.35 or 0.46ppm/ml in 100L doesn’t matter too much. Maybe I’ll just assume it’s 0.4ppm/ml and likely still in a reasonable range when I do my next ICP Dec 2025.

 

[Randy Holmes-Farley Verified Community Expert]

You triggered a memory. I weighed the container and multiplied the weight by whatever 500ml/1gallon fraction equals with the correct units. That’s where 180g came from. Where I got the 0.46 ppm/ml I’m not sure but seems to be based on your recipe.

No obvious way to answer the question of what the actual ppm is, which is why I now prefer to diy stuff. I supposed whether it’s 0.35 or 0.46ppm/ml in 100L doesn’t matter too much. Maybe I’ll just assume it’s 0.4ppm/ml and likely still in a reasonable range when I do my next ICP Dec 2025.

I agree it doesn't matter too much. In the end it comes down to whether BRS made a mistake (intentional or accidental) in the fill of the container, or whether they are using a not fully hydrated product. That latter is usually more expensive, but they may have gotten some sort of bulk deal that made it desirable for them.

 

[rishma]

I agree it doesn't matter too much. In the end it comes down to whether BRS made a mistake (intentional or accidental) in the fill of the container, or whether they are using a not fully hydrated product. That latter is usually more expensive, but they may have gotten some sort of bulk deal that made it desirable for them.

I’m actually going to ask them.

 

[Randy Holmes-Farley Verified Community Expert]

I’m actually going to ask them.

That works too. lol