part 3a with magnesium

[green wrasse]

For those of you that use the mag part do use the dead sea magnesium and if so where would you get it? And is it a liquid or pellet or what? Or could I just use Seachem and if so would I use it at the same rate of 5 cups?
Thanks

[Crit21]

I wouldn't use either as a substitute for the Epsom and mag chloride. The dosage for Part 3b in Dr Randy's article is for a specific amount of Epsom salts and magnesium chloride hexahydrate only, and is meant to maintain a rough balance based on the use of the improved 2-part formula.

After using the correct dosage of Epsom and mag chloride according to the article, wait a day or so, then test your mag levels. If the test shows your mag is low, you might use the Seachem (dry), and dose only after consulting the calculator: http://reef.diesyst.com

I don't know what instructions come with the two additives you mentioned, but I wouldn't recommend adding either without knowing your current and desired mag levels, what exactly is in the additive, how much to add, and what to expect as a result.

Epsom salts are cheap and easy to find, and I'm hearing that pure mag chloride flake is becoming more common right now. If you're using Randy's formula, it seems safer to me to use his recommended Part 3b (or 3a if you can't find the mag chloride).

[racer69]

It will be fine to use the Seachem with the homemade 2-part or any other ca-alk additive. What is your mag level now, and what do you want to maintain it at? The calculator Dan listed above will tell you how much Seachem to add to get your desired results. If you have problems with it, just post your mag parameters and your desired, and I will calculate it for you.

[green wrasse]

I havn't tested it yet waiting for Scott to get test kit in so I don't know but I was definitly was going to chech it before adding. I was just wondering because in the recipe that Todd gave says 3a disolve epsom salts (3 cups) and mag. chlo. hexa. sold by the dead sea co. (5 cups) in enough water to make1 gal total volume.
But I will try Scott again tomorrow and if not I think neptunes has 1 that calculator you posted is very helpful but I do want to know my level before I add anything
Russ

[Crit21]

There's a difference between keeping your magnesium levels at optimum levels and adding part 3B to balance Dr Holmes-Farley's formula.

The Part 3 mixture is specifically formulated to balance the Part 1 and 2 formulas by eliminating the buildup of sulfate over time (i.e., when you use Epsom salts--magnesium sulfate--without magnesium chloride).

The point I was trying to make earlier was that when using the Holmes-Farley supplement it would be best, if you can find it, to use 3B (mag chloride and mag sulfate) to balance the chemical equation.

Seachem says its magnesium supplement includes chlorides and sulfates. The issue is that it probably isn't formulated in the same ratio as Part 3B, so while it will increase your magnesium levels to desirable levels, it won't balance out the Holmes-Farley system, which should be your goal if using that system.

From what I hear, even if you follow the Holmes-Farley dosing exactly, you may still have to supplement additional magnesium if testing indicates it's necessary.

Of course, you can use 3B or any other mag supplement any time your mag level is low.