Magnesium Mixture: Randy's 2 Part DIY

[zoozilla]

Hello Randy -

Just got all of the materials today for the DIY 3 Part Calcium/Buffer/MAG. I had a question regarding the Magnesium options for Recipe #1. What are the benefits of utilizing a Mixture of Epsom Salt and MAGFlake? Since there is a build up of Sulfates over time when using Epsom Salt, can I just omit using Epsom and use 8 cups of MAGFlake for this recipe instead?

(Are there adverse affects on the chemistry if using 8 cups of MAGFlake?)

Thanks

[Randy Holmes-Farley]

If this were a stand alone supplement, the MAG flake alone is an OK way to go, although a 10:1 MAG flake to Epsom mixture is a tad better:

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

HOWEVER, when used with the rest of the DIY two part, which itself adds a lot of chloride from the calcium chloride, the Epsom salts are useful to keep the chloride from rising too much relative to sulfate. So in that case, more Epsom is needed and it is more important, hence the different ratio in the magnesium part.

[zoozilla]

Thanks Randy...

[shikhyung]

Hi Randy,

This is Shin, regards to the use of Epson and MagFlake for the Magnesium. Does it necessary to use it after the use 1 gallons of each of the 2 receipe 1 part? I almost finish a gallon for each part, but the reading from the Magnesium seems to stay the same. Thanks.
Shin.

[Billybeau1]

It is not necessary if you dont need it. His recipe is just a guide. If you test mag and it is where you want it, no need to add any more. :)

[Randy Holmes-Farley]

The only concern with never using if (if, for example, you are doing water changes with a salt like Oceanic that has high magnesium), is that you may slowly cause chloride to be elevated relative to sulfate. But if magnesium is above 1300 ppm, there is no need to add it.

[shikhyung]

Thanks for the answers, I currently use the Red Sea Salt, and change 5 % weekly. The only I add to the 5% is Cal , the AKL and Mag are on line. May I ask to the next questions(dummy questions) :
1-slowly cause chloride to be elevated relative to sulfate What this will do to the tank or coral?
2- If I use the Magnesium receipe, do I use the full amount as instruction in the receipe (somewhat 680ml), or just enough to bring the Mag level above 1300ppm?
Thanks. Shin.

[Randy Holmes-Farley]

slowly cause chloride to be elevated relative to sulfate What this will do to the tank or coral?

I don't really know. It never happens in the ocean, so oceanographers have not typically looked at it, a nd hobbyists have not.

These articles discuss it more:

Simulating the Effect of Calcium Chloride and Sodium Bicarbonate Additions on Reef Systems
http://web.archive.org/web/20010606111158/http://www.animalnetwork.com/fish2/aqfm/1998/dec/bio/default.asp

Additional Simulations: The Combined Effect Of Calcium Chloride
/Sodium Bicarbonate Additions And Water Exchanges
http://web.archive.org/web/20010210223756/http://www.animalnetwork.com/fish2/aqfm/1999/feb/bio/default.asp

If I use the Magnesium receipe, do I use the full amount as instruction in the receipe (somewhat 680ml), or just enough to bring the Mag level above 1300ppm?

Good question. What is the magnesium now? The recipe is intended to not require testing, and I doubt things will get far off if you always add the recommended amount, but testing and adding just enough is likely fine.

[shikhyung]

What is the magnesium now?
I have a spread sheet record the numbers, but I did not remember was it before or after water change. But it is ranging between 1280 (+10ppm) to 1320 (- 10ppm). The +/- is for the error. From the calculator if I doze full amount, it could be 1340 to 1375 afterward...Is it safe? Thanks.
Shin

[Randy Holmes-Farley]

Yes, it is safe, but it would also be OK to not dose it. :)

[shikhyung]

Thanks. Shin.

[Randy Holmes-Farley]

You're welcome.

Good luck. :)